There is something missing from fashion in 2016. It hasn’t been there in any of Alicia Vikander’s Louis Vuitton romantic, softly scoop-necked gowns, on the premiere tour of The Light Between Oceans. It wasn’t there on the best-dressed lists of the Met Gala in May, which were dominated by Beyoncé in high-necked skin-toned latex. It didn’t happen at Cannes, where Bella Hadid slayed all pretenders to her fashion throne in a red satin dress with a deep V to the waist, the smooth line from navel to waist accentuated by her swept-up hair. It was nowhere to be seen at the Oscars, where Jennifer Lawrence’s black lace Dior gown was free of obvious cantilevering.

Facebook Twitter Pinterest Bella Hadid at Cannes. Photograph: Samir Hussein/WireImage

“Whatever happened to the cleavage?” asks the new issue of Vogue. The squished-together, hoicked-up presentation of bosoms has all but vanished from fashionable circles. Scaffolding breasts under the chin and framing them with a low-cut top, which has for decades been a shorthand for allure – the four-four-two of getting dressed up for a night out, if you like – is over. The go-to after dark neckline from catwalk to high street this year is a straight horizontal line that exposes the shoulders. The must-have Gucci blouses on Net-a-Porter have elaborate pussy bows that demand to be fastened around the neck. Any self-respecting It girl of the moment knows that the photo the paparazzi want is the one in gym leggings and a crop top, exposing this year’s must-have ab-crack. Eva Herzigová, whose 1994 Wonderbra advert (“Hello Boys”) did more than any other image to put cleavage at the bullseye of sex appeal, has this year chosen for her most high-profile appearances a pie-crust collared white blouse under a trouser suit for the Vogue centenary party, and a buttoned-up denim coord at the Venice film festival. I think we can safely call that a goodbye.

Facebook Twitter Pinterest Eva Herzigová wore a pie-crust collared white blouse under a trouser suit for the Vogue centenary party. Photograph: Jeff Spicer/Getty Images

The odd part about this, though, is that you would be hard pressed to look at the year 2016 and say – yay, isn’t it brilliant how women don’t feel any pressure to have perfect bodies any more. I mean, I’m all for looking on the bright side, but when a recent survey by Dove found that just 20% of women in the UK are confident about how their body looks, I don’t think we’re quite ready to punch the air and say: “Hurrah, thank goodness all those issues about women’s plummeting body image are solved.” Women are as critical of their physical selves as ever, and as likely to spend their time and money on bodily self-improvement. But when it comes to buying bras, that money is no longer spent on structures that create the once all-important effect of two extra large scoops of ice-cream upholstered by scalloped lace. A third of Net-A-Porter bra sales are now soft bras, without underwire. Elle Macpherson has returned to the lingerie market with a range that foregrounds comfortable, triangle-shaped bras, citing research that shows young women prefer this type of lingerie. Even Victoria’s Secret, spiritual home of the pneumatic cleavage, is marketing a new range of “bralettes” without underwire.

Facebook Twitter Pinterest Eva Herzigová’s 1994 Wonderbra advert.

This is not, to be clear, about an anything-goes era. There is still very definitely an ideal, when it comes to bosoms. But what Naomi Wolf once dubbed the “official breast” looks different now than it did in the first heyday of cosmetic surgery. The new look is what fashion insiders, with their wilful clinging to the fashion singular, have long dubbed “a 70s boob”, for its aesthetic connection to the soft-focus, earthy femininity of that decade. It is Jane Birkin in a cotton T-shirt, or Michelle Pfeiffer in Scarface (1983, but still). It is also Elizabeth Debicki in this year’s The Night Manager, all swan-like neck and clavicle and sweeping cream satin.

Victoria’s Secret, spiritual home of the pneumatic cleavage, is marketing a new range of 'bralettes' without underwire

As anyone who has known the particularly grating discomfort of wire digging into soft flesh will testify, the demise of the push-up bra is a step in the right direction, even if it is not a happy ending. The cleavage’s function as an essential part of looking glamorous but a barrier to being taken seriously in a professional context was a tiny, irritating example of the kind of double standards with which women endlessly have to deal. And the body parts that are being showcased instead – shoulders, upper arms and abs, for the most part – might not be attainable by all, but at least they speak of strength and action, rather than the quivering spectacle of a trophy cleavage. The way one presents to the world is always a power play: a statement about what you can offer, and what you expect in return. Breasts piled together like a pair of cream buns do not make a subtle statement, to that effect – a fact that Wonderbra nailed, back in 1994, in the way that only the straightforward wording of ads can.

Facebook Twitter Pinterest The new 70s boob look: Michelle Pfeiffer in Scarface. Photograph: Sportsphoto/Allstar

Look a little closer, however, and there is a subtle but significant difference between the 70s boob of the actual 1970s, and the new 70s boob. The new version is not so much natural, as faux-natural. It may not be hoicked, but it is certainly perky. The look is as much about breasts that don’t need a bra, as it is about not wearing a bra. In celebrity-ville, there are a lot of cosmetically enhanced breasts, and cosmetically enhanced breasts do not need bras. In this way, the goalposts of the perfect body have been moved, once again. Cosmetic surgery has a insidious impact on the beauty and fashion industries. Just as the effect of rhinoplasty and fillers is aped by Superdrug counters bulging with cheap contouring creams, so the rise of silicone buoyancy has created a new market for lace bralettes. The end of cleavage does not mean the path to a more realistic, more diverse, more empowering world of female body image has got any easier. But at least we get to make the journey in more comfortable underwear.

• This article was amended on 4 November 2016 to correct the spelling of “silicone buoyancy”.