The term “romantic comedy” these days covers a lot of light entertainments that only notionally meet the genre requirements: They pivot on relationships while just glancing at romance, and are packed with dialogue that’s zappily delivered but not all that funny. “The People We Hate at the Wedding” is one such nonromcom. Sporting a game cast and efficient sitcommy pacing, it looks and sounds the part just enough to keep you diverted — until you notice, as the credits roll to upbeat electropop, that you haven’t laughed once. Starring Kristen Bell, Ben Platt and Allison Janney as the blundering American relatives lowering the tone of a posh English wedding, this straight-to-streaming Amazon release attempts to bring a faintly risqué, expletive-laden millennial sensibility to Nancy Meyers terrain, and never quite finds the sweet spot.

That’s disappointing coming from director Claire Scanlon, a TV comedy pro whose debut feature, the much-loved 2018 Netflix sleeper “Set It Up,” had a genuine throwback spark to it: It too was more frothy than funny, but made up for it with a proper understanding of star chemistry and the genre’s rules of attraction. Keeping multiple storylines afloat with occasional split screens and hip needle-drops galore, the former editor does her best to pull off a similar new-old-school trick. She’s largely thwarted, however, by a script from sister act Lizzie Molyneux-Logelin and Wendy Molyneux (TV’s “Bob’s Burgers,” the upcoming “Deadpool 3”) that hasn’t even the warmth to counter its limited wit.

The hated people of the title, it turns out, are our core trio of characters — a mostly unlikable bunch that the film seemingly invites us to root for by virtue of their sheer prominence. (Or, depending on the audience, the fact that they’re the only “normal” Yanks in a sea of cut-glass Brits and lascivious Continental types.) In an arch comic device that is never followed through, a formal voiceover lays out their backstory in the style of a fairytale: Outgoing American Donna (Janney) settled in Britain in the 1980s, marrying rich, suave, philandering Frenchman Henrique (Isaach De Bankolé) and giving birth to a daughter, Eloise, before divorcing and moving back to Indianapolis. 

There she married an all-American schlub and raised two more children, Alice and Paul, in comparative suburban dullness — annual extended visits from Eloise excepted. As children, the half-siblings were close; as adults, their relationship has become rather more strained. Tech PA Alice (Bell) and aversion therapist Paul (Platt) resent Eloise (Cynthia Addai-Robinson) for her wealth, beauty and floating-on-air glamor. With Alice nursing the trauma of a recent miscarriage and a dead-end affair with her married boss (Jorma Taccone), and Paul insecure in his relationship with snippy boyfriend Dominic (Karan Soni), perfumed invitations to Eloise’s lavish wedding across the pond are unfortunately timed. 

After much pleading from their mother, they agree to go — only to sabotage proceedings from the off, drunkenly voicing grudges in the face of Eloise’s prim-and-proper hospitality, drunkenly ruining the bride’s admittedly hideous bachelorette party, and drunkenly vomiting into nearby greenery whenever the script needs a fresh hit of mild gross-out humor. “My god, you kids still barf a lot,” notes Donna, whose own gesture towards substance-based wackiness is oversharing a bit whenever she pops a pot gummy. Janney, though first-billed in the ensemble, is least generously served by the narrative, often receding from the hijinks entirely.

Her inevitable rekindling of the flame with Henrique — as is mandatory in any wedding comedy featuring estranged parents of the bride — is the sketchiest in a clutter of nominally romantic subplots that also sees Paul pondering a menage-a-trois with Dominic and their dishy older host Alcott (Julian Ovenden), while Alice hovers uncertainly between her unavailable lover and the kind, “Paddington”-loving cutie she meets on the flight to London. He’s played by Dustin Milligan, recycling wholesale his sweet-hot-dork shtick from “Schitt’s Creek,” which is still enough to make him the most amiable figure here. Just as he and Bell get a snappy rapport going, this over-busy film cuts away to less agreeable proceedings, involving people you’d never voluntarily spend time with. 

A final-act flood of tearily revealed secrets ostensibly makes sympathetic sense of some sociopathic behavior, but it all comes rather too late to endear any of these unwelcome wedding guests to the audience. Bell and Janney both have ample experience of sashaying with some pizzazz through lesser material, and do so again here; Platt, less of a natural comedian, tries and mugs a little too hard. But it’s the sheer surreal presence of Ivorian arthouse icon De Bankolé, taking to proceedings as organically as a ballerina in a barn dance, that may stick most in the memory once everything else about this marshmallow movie fades. For better or worse, this will always be the film where, at another effortfully zany juncture, the muse of Jim Jarmusch and Claire Denis turns to the star of “Dear Evan Hansen” and utters the line, “Paul, are you peeing on my feet?” That’s not nothing, but it’s not the stuff of vintage romcoms either.