The thing I like most about Physical is the show’s unwavering refusal to be likeable. Headlined by Rose Byrne and her bountiful Jaclyn Smith-worthy hair, Apple TV+’s acerbic 1980s comedydrama about a San Diego housewife who finds self-purpose with the advent of aerobics is driven by the sting of self-loathing. Now in its second season, the series is full of warmly amusing period detail and curt dissatisfaction; for the main characters, happiness is almost always an illusion that dissipates all too quickly. The lack of cuteness is compelling.

The strongest voice – so strong that it’s almost a separate character that deserves its own billing – is the inner monologue of Byrne’s Sheila Benson. It’s been there since the first sighting of Sheila in 1981, dismissively looking at herself in a mirror and passing a verdict she’s desperate to share but terrified of others knowing. “Do you really think you’re pulling this whole thing off?” she asked with rhetorical bitterness. Every instalment since has stress-tested that notion, so much so that the line between bending and breaking is no longer clear.

The psychological make-up of Sheila is steadily revealed to be staggering: a remnant of 1960s student activism in the era of Ronald Reagan, a harried wife and mother who can only find fulfilment when treating exercise as an exorcism, the possessor of deep childhood trauma, and a serial deceiver whose bulimia has her ritually bingeing and purging junk food in a motel room. Byrne carries all of this, whether it’s meant as Sheila’s armour or her possible annihilation, with a revelatory nuance. You can see her many pieces all at once.

Created by Annie Weisman, whose previous writing and producing credits include Desperate Housewives and The Path, Physical takes the classic male anti-hero and inverts the concerns – a real family instead of a crime family, a fear of self-expression instead of callously acting out. Like Sheila, the show has acquired its own identity: there’s a trademark shot of Byrne’s protagonist, head on as if the camera and the watching audience is now that mirror, which almost demands you make a snap judgment as you see her steeling herself.

The half-hour episodes have an almost blithe pacing, as the show often dispenses with the connective tissue that fills out an hour-long drama, but the second season has dug satisfyingly deeper. Sheila’s hunger to have a successful aerobics empire – she wants to be on TV – has a jarring impact on her. She wants to leave her self-important husband, Danny (Rory Scovel), but he beats her to the punch by vowing to do better. “I’m going to pick up the slack for my gender,” he pledges, defeating Sheila by admitting his own defeat.

She has an awkward push-and-pull dynamic with her sometimes best friend, Greta (Dierdre Friel) that allows for both their needs, while Sheila also has an affair with her progressive husband’s adversary, pious real estate developer John Breem (Paul Sparks). The show’s easy sidestepping of realism to flirt with the fantastical or establish an absurd jauntiness made Breem and his flattened poker face a foil for Sheila and advanced one of Physical’s underlying fascinations: what happens when we make commercial success a personal goal.

Hanging over the series, which has advanced from 1981 to 1982 over two seasons, is an initial flash forward to a domineering Sheila in 1986, complete with terrified staff and some satisfied ambitions. It suggests a destination for the story, and given that Physical is an Apple TV+ series it may well get there. Since it launched in late 2019, the tech giant’s streaming service has had a simple but successful philosophy of backing creators to make the show they want and not overtly fiddling with the result.

There have been setbacks: the star-studded Morning Wars, intended as a flagship, ran off the rails in its second season (there will be a third – save me!). But for the most part Apple TV+’s bespoke catalogue – they have no old hit 1990s sitcoms or reality shows – has been a success. Three seasons of Dickinson and For All Mankind, respectively a meta-19th century comedy and space race alternate history, plus everyone’s favourite feelgood coach Ted Lasso, Foundation, Mythic Quest and Servant set a benchmark.