Brett Goldstein burns through a little of his “Ted Lasso” capital with “All of You,” a “When Harry Met Sally” platonic-friends-can’t-stay platonic romance co-starring Imogen Poots.

The friends “since uni” story, co-written by Goldstein, is at its best when our not-a-couple are just bantering — drug jokes, a wake for her dad joke that nobody who hears it will ever forget — supporting one another in times of crisis, with one of them plainly longing for something that will never be.

It’s after Simon’s paid for Laura’s “Soul Mates” AI-perfect matchmaking, after he’s been to her wedding and after he was the one to rush her to the hospital so that she could give birth that the affair begins. That’s when the film settles into a struggle to transcend cliches.

Affairs go in and out of fashion in the culture, but “All of You” highlights the fact that it’s not just movies about them that are formulaic. Affairs themselves have become cliches.

She has a baby and a “vulnerable moment” — a late night visit, impulsive sex on the floor. She sets him up with a friend (Zawe Ashton) who clicks with him well enough for them to move in together, only for Simon’s new love to figure out who his true love.

Simon and Laura engage in cheaters’ magical thinking — a fantasy about running off to America for “non-stop sex and drugs.”

Even the epiphanies they’re sure to come to — she “won’t leave Lukas” (Steven Cree), her Scots husband — have the air of trite tropes.

“We hurt people and they don’t even know we’re doing it to them.”

Goldstein leans into soulful suffering as a journalist who doesn’t believe in this new foolproof “find the one person we’re meant to love” digital “test.” Poots makes Laura a beaming believer, pretty enough to take advantage of “just a friend” Simon and impose on him, even as she ignores how they connect.

He’s there with just the right laugh at her speech at her dad’s wake, or with a little Molly at the club where she’s hoping he’ll take a fancy to her “Andrea the Giant” (Ashton) buddy.

The movie moves on from the witty, callow quips of youth as they both take a stab at “being grownups…It’s AWFUL.”

Couplehood and its “farmer’s market” visits are not for Simon. “What goes on there? Are they selling farmers or something? Putting them up on plinths for display?”

What replaces that is sober and sad and so very over-familiar — a rendezvous by the sea, furtive phone calls, her protests that he’s “stalking” her when she’s the instigator — as to be almost laughable itself.

Honestly, who takes a checklist of all the things one does when having an affair, as seen in the movies, into an affair? That’s how this plays.

The acting is good, as Poots is an old hand at this sort of lovesick romance and Goldstein shows off character traits that most of us haven’t seen him attempt. But few of the heartfelt moments land and none grab the pathos that Goldstein and co-writer/director Walter Bridges are attempting.

It isn’t just morality that keeps us from “rooting for them” as a couple. We can’t decide if they’re rooting for them.

Rating: R, drug abuse, sex, profanity

Cast: Brett Goldstein, Imogen Poots, Zawe Ashton and Steven Cree

Credits: Directed by William Bridges, scripted by William Bridges and Brett Goldstein. An Apple TV+ release.

Running time: 1:38