This year, the Cannes Film Festival kicked off with a restoration of Jean Eustache’s 1973 ménage à trois scandal “The Mother and the Whore” and concluded with a screening of controversial Palme d’Or winner “Triangle of Sadness,” creating an odd kind of symmetry for the event’s 75th anniversary edition, between which I somehow managed to screen all 21 films in competition. Made half a century apart, Eustache and Östlund’s rhyming triangles were hardly the only parallels to be found at Cannes — though anyone who’s ever binge-watched movies at a major festival knows the feeling of such connections, often just a fluke of the order in which you see movies whose images and ideas inevitably resonate with one another.

Consider this could-be coincidence: Roughly midway through Östlund’s influencer-skewering satire (a fitting follow-up to 2018 Palme d’Or winner “The Square”), a black-tie dinner aboard a posh ocean cruise goes sideways, touching off an outrageous sequence in which the disgraced attendees, puking every which way, wind up swimming in their own effluvia. Until this point, “Triangle” presents itself largely in aspirational mode, poking pinholes in the characters’ rarefied bubble. But this vom-arama creates a wonderful rift in the film’s high-class veneer, bringing everything down to the crudest of bodily functions (one character, erupting from both ends, alternates between sitting on and bending over her lavatory), à la restaurant scene in “Monty Python’s The Meaning of Life.”

It might well have been the scene of the festival, were it not for the perverse programmer who scheduled art-house punk Quentin Dupieux’s “Fumer Fait Tousser” right after, an absurdist smoking-themed comedy which features its own epic barf gag — and just like that, Östlund’s out-there set-piece seems to have met his match (not really, though the novelty certainly feels diminished). Another example might be donkeys, which factor into both “Triangle” and Jerzy Skolimowski’s “EO.” The latter is a pro-animal, human-skeptical fable — imagine a modern riff on Robert Bresson’s “Au Hasard Balthazar” crossed with Countess Ségur’s “Memoirs of a Donkey” — which follows an ex-circus donkey as he wanders across Europe, interacting with people who abuse it, or the earth, or both. To my surprise, the film delivers much of the emotional punch found lacking in this year’s competition. Jet-lagged and sleep-deprived, we critics tend to sit fragile in front of the sacred Cannes screen. In such a state, it doesn’t take much to provoke a feeling of cinematic ecstasy, which makes the lack of such cathartic connections in this year’s relatively mediocre lineup all the more disappointing.

As far as I’m concerned, the festival’s defining scene occurs in “R.M.N.,” a rich and densely layered — but by no means impenetrable — social parable from director Cristian Mungiu (the talent behind “4 Months, 3 Weeks and 2 Days”). Told in the cool, steady-handed style of Russian auteur Andrey Zvyagintsev (“Loveless”), “R.M.N.” takes place in a rural Romanian town, where the manager of a bakery sparks controversy when she hires two South Asian immigrants to help at the factory. She has no choice, since none of the locals will take the low-paying jobs, but that doesn’t stop the angry, openly racist villagers from revolting. Mungiu lets these characters speak for themselves, filming the heated objections raised at a town hall meeting over the course of a 17-minute, fixed-camera shot, over the course of which the community’s social contract seems to collapse. Watching “R.M.N.,” I was reminded of Robert Benton’s “Places in the Heart,” in which widow farmer Sally Field and blind brother-in-law John Malkovich stand up to the Ku Klux Klan. Setting his film nearly 90 years later, Mungiu gives us an equally chilling story of bigots who don giant bear costumes in order to threaten unwanted outsiders and the unlikely heroes who challenge them.

Two other competition films concerned with immigrant characters both felt like the work of two-time Palme d’Or winners the Dardenne brothers in their documentary realism: “Mother and Son” and “Tori and Lokita.” The latter actually was a Dardenne movie about two Ghanian refugees living in Belgium who pose as siblings in order to help 16-year-old Lokita get her papers. The authorities aren’t buying it, which forces the kids to find their own patch to the problem by working for a local drug dealer. At first, they just make deliveries, but the boss exploits his power and pressures Lokita into various degrading sexual situations as well. The film’s style is classic Dardennes, though they’ve stripped away the moral complexity that typically makes their work so rich, ending the film abruptly, all but accusing passive audiences of contributing to the broken immigration system that made such an upsetting situation possible.

Léonor Serraille’s “Mother and Son” is subtler, but frustrating in other ways, straining to cover nearly two decades in the life of a single mom from Ivory Coast who moves to France with her two kids. It’s predictably difficult for her to find work and raise her boys, who rebel against the revolving cast of father figures she brings into their lives. With loose echoes of “Moonlight,” Serraille dedicates separate segments of the film to each of the sons, who push back against the system in different ways, one struggling to assimilate, the other fighting to remain true to himself.

As exercises in empathy, these films touch deep chords, though none seems to have resonated more with audiences than Lukas Dhont’s “Close,” which had Cannes audiences sobbing with recognition and regret. (The two youngest directors in competition, Dhont and Serraille are both former Camera d’Or winners — for 2018’s “Girl” and 2017’s “Jeune femme,” respectively — whose second features set perhaps unfairly high expectations.)

Dhont’s film centers on the close-as-brothers friendship between two 13-year-old Belgian boys, evocatively conveyed via inseparable adventures and sleepovers in the film’s first half. Then an innocuous question at school introduces the notion of homophobia to their seemingly pure friendship, and the two start to take their distance, with tragic consequences. Dhont has created a golden-hued, “Velveteen Rabbit”-style tearjerker here, playing on our memories of childhood, though the film’s twist — which turns it into a film about something else entirely — reminded me of the trick Christopher Isherwood pulled in “A Single Man,” dealing with a real-life breakup by imagining the death of his partner. Doing so has undeniable emotional impact, but also provides an easy out, substituting grief for the possibility of reconciliation.

Another Belgian-made offering, Felix van Groeningen and Charlotte Vandermeersch’s “The Eight Mountains,” also focuses on an intense childhood friendship, but follows it over many more years, giving the bond between two Italian boys the chance to evolve and mature over several decades. This film, much of which takes place high in the Alps, was shot in a surprising 4:3 Academy ratio, and though there’s no shortage of gorgeous scenery, the format concentrates our attention on the characters in the foreground: Pietro, a city boy who grows up to become a globe-trotting travel writer, and Bruno, the last child born in a shrinking mountain village, who can’t imagine any other life from building houses and making cheese. So many of the Cannes movies felt too long this year, but every minute of this tender two-and-a-half-hour portrait makes it that much easier to share the special connection between these two.

Which brings me to the competition film that caught me most by surprise. It’s been more than a quarter-century since prolific Italian director Mario Martone had a film in competition at Cannes (the Venice Film Festival has been his home in the interval), so expectations were rock bottom for this nuanced redemption drama, infinitely better than the sentimental title implied (blame that on the Ermanno Rea novel from which it was adapted). Yet another look at a lifelong bond between boys, this one carries with it an uncommon maturity, as Martone takes his time to reveal what the movie is really about. “Nostalgia” opens with the return of one Felice Lasco (Pierfrancesco Favino), who wanders the streets of his native Naples, tending to the mother he left behind, now widowed and alone in a pathetic flat. Little by little, we learn that in the years Felice was away, his closest pal has become a fearsome gangster (Tommaso Ragno). Some friendships never really end; others probably shouldn’t have existed in the first place.

The film that might more aptly have been named “Nostalgia” came from American helmer James Gray (“The Lost City of Z”), better known abroad than he is in the U.S. It’s perhaps for this reason that his 1980-set memory piece/complex mea culpa, “Armageddon Time,” seemed to be the favorite film of so many foreign critics at the festival. Casting Anne Hathaway as his mother and Anthony Hopkins as the good-humored granddad who encouraged his artistic side, Gray presents a childhood more privileged than most (but not Valeria Bruni Tedeschi, whose “Forever Young” depicts the director’s younger self receiving the news of her lover’s death via her personal butler). But he’s tough on his loving, liberal Jewish family, who seem oblivious to their own racism, plucking their son out of the newly integrated public school in order to send him to a private academy (where Donald Trump’s dad was a donor) that looks like boot camp for young Republicans — a chapter that has presumably informed his entire career, although the confessional film feels less like his “The 400 Blows” or “Belfast” than something he had to get off his chest.

After seeming to lose his way in recent years, David Cronenberg makes a comeback to the squirm-inducing body horror that defined his early career with “Crimes of the Future,” casting Viggo Mortensen as a performance artist who keeps producing mutant organs, which partner Léa Seydoux tattoos and then surgically removes in underground shows. The movie’s big on ideas — the most delicious of which is the fresh metaphor it provides for Cronenberg’s artistic corpus, in which his body of work can now be seen as having been incubated and extracted one cancerous tumor at a time — but doesn’t take them in an especially interesting direction.

Still, it’s far more exciting to see him retreading familiar ground than tiresome French auteur Arnaud Desplechin, whose “Brother and Sister” feels like the umpteenth retread of emotionally damaged family members trying to work out their differences. This one literally amounts to a strand from “A Christmas Tale” stretched to feature length, which wouldn’t be so bad, if we believed the rift between Melvin Poupaud and Marion Cotillard’s characters in the first place.

Plausibility was a big problem with Cannes’ two Korean entries, Park Chan-wook’s “Decision to Leave” and (Japanese helmer) Kore-eda Hirokazu’s (Korea-set) “Broker,” both incredibly well-made films, if only we bought the characters’ behavior. In the elegantly restrained erotic thriller “Decision to Leave,” a married detective (Park Hae-il) falls for a woman (Tang Wei) suspected to have killed her husband. He convinces himself that she’s innocent, until her next husband turns up violently murdered — which she may have orchestrated in order to bring the cop back into her life. Romantic, sure, but hard to swallow.

“Broker” proves even tougher, as affable “Parasite” star Song Kang-Ho plays a man who arranges to sell abandoned babies on the black market, but is so bad at it that he winds up adopting the kid — and their murderer-prostitute mother — himself. Both films have their fans, but they ask audiences to check their brains at the door.

My own brain was probably too tired by the time I got to Albert Serra’s “Pacifiction,” a long, slow-burn political intrigue set in seemingly idyllic Tahiti. The movie turns on rumors that the French military may be planning a nuclear test nearby, though I dare you to stay awake while a government functionary (Benoît Magimel) tries to put a stop to things, knowing a nuke would ruin the cushy, vaguely corrupt life he’s established for himself on the island.

Then again, it’s no worse than Claire Denis’ ridiculous “Stars at Noon,” the French director’s second English-language film, with dialogue that sounds like it was written by Joe Eszterhas (“Are you for sale?” “For a price, I’ll sleep with you.”). Hot and steamy in all the wrong ways, the movie amounts to a callow “Year of Living Dangerously”-style sex fantasy, in which an American journalist-turned-prostitute (Margaret Qualley) stuck in Nicaragua tumbles in and out of bed with the stranger (Joe Alwyn) who just might be her ticket out of the country.

Contrast “Stars at Noon” with the nearly-three-hour Iranian film, “Leila’s Brothers,” which also centers on an exasperated young woman, and you get an idea of just how diverse Cannes’ competition section can be. In Saeed Roustaee’s novel-rich saga, a family tries to pull themselves out of poverty, but can’t convince their self-interested patriarch to invest his savings in their future, instead of his own glory. Accustomed to simpler Iranian stories in which a kid loses his shoes (“Children of Heaven”) or girls try to sneak into a soccer match (“Offside”), I was surprised by the complexity of Roustaee’s plot, which serves to disguise his critique of a society that doesn’t take well to dissent.

Still, Roustaee’s film has nothing on Ali Abbasi’s “Holy Spider,” an Iranian true-crime story so damning, it could only be made abroad. As tense and brutal as a classic Brian De Palma thriller, the film tells of a religiously motivated serial killer who targeted prostitutes and the police who did little to stop him, until a female journalist helped catch him. If you think the first part of the film sounds rough, wait’ll you see how society reacts when the man is apprehended, with a segment treating him like some kind of vigilante hero.

Half-Egyptian director Tarik Saleh was likewise obliged to make “Boy From Heaven” outside of Egypt (where he was banned following “The Nile Hilton Incident”), though doing so allowed him to challenge the government in a power-grab thriller that plays like “House of Cards.” The film imagines how a hick university student, newly enrolled in Al-Azhar University, might be manipulated by State Security in an elaborate scheme to influence the selection of the next Grand Imam.

Meanwhile, Kelly Reichardt’s “Showing Up” is as slight as “Boy From Heaven” is complicated. The American director reteams once again with Michelle Williams, who plays a sculptor scraping by in Portland, Ore., and that’ll be more than enough for Reichardt stans, though I found it thinner than thin, especially compared to a standout like Maria Kreutzer’s “Corsage” in the relatively less prestigious Un Certain Regard section. “Corsage” stars Vicky Krieps as Empress Elisabeth of Austria and pretty much torpedoes the sweet, Harlequin Romance version of “Sissi” so beloved by Europeans raised on the Romy Schneider movies (in another sneaky symmetry, Cannes press-screened “Corsage” the same day as the new Schneider doc “Romy, a Free Woman”).

Saving the least for last, there’s also Kirill Serebrennikov’s “Tchaikovsky’s Wife,” a relatively restrained period piece from the virtuosic Russian director — a dissident whose style often upstages his impenetrable scripts. That’s true too of his latest, which seeks a fresh understanding of the woman who married the great composer. He was gay, his wife later committed for hysteria and the ill-fated union lasted about as long as this rather exhausting movie, which drifts between hallucination and highly implausible interactions so freely that we’re left to read it for what it is: an impenetrable political statement about a country that seems to have lost its collective mind in recent months. For the Cannes programming team, selecting it was also a statement, defying those who have asked for an artistic ban on Russian films. Taking this year’s weak selection as a whole, we can’t but discern a similar resistance to calls for gender parity, as Kreutzer’s “Corsage” and Mia Hansen-Løve’s “One Fine Day” (in Director’s Fortnight) would have easily held their own opposite the men Cannes welcomes with open arms.