I feel like it's gone through several discrete stages:
First, elective PS was for the elites, the film stars, the rich and idle, basically. Nobody normal felt pressure to have it unless they had dysmorphia or a real disfiguremen via birth or accident. Mostly it was seen as inadvisable and something for the idle rich and the old. That's key.
Then it became affordable - at least through the selling of debt - to the masses a bit more and people got it younger, but pretended they didn't, because it was still seen as a bit pathetic to care that much as well as an admission you 'needed' it. The idea was to pretend you were 'naturally' suddenly tighter, fresher, lifted, whatever. Women would deny they got breast implants when they were bloody obvious. Actresses who were clearly pulled tighter than a drum, had a obviously frozen face, or suddenly had a hairline an inch higher denied they did anything and put it down to some fancy creams or yoga or whatever.
Now? It's become a consumer-age status symbol to buy new lips, tits, whatever, to the youngest demographic who 'need' it least. The users brag about it, because they think being able to pay cash for this stuff makes them enviable, as it translates into being more sexually competitive, which is tied in their minds into success. Consumerism is power, therefore buying your looks is power, with this veneer of the faux 'feminist' empowerment' of doing whatever, whenever and pretending it's a power move. The sad reality is customers and rather deep dependencies have been created for life. End goal of the industry, I guess. Get them young, as young as possible, rather than hoping customers seek you out halfway through their life or later.
I agree the Kardashians started this final stage, although Kim tried to pretend she didn't have procedures to obtain her allegedly 'enviable' and wholly disproportional backside. Kylie at one point tried to deny having lip filler when she was pimping that stupid lip kit on the basis using it would give you much fuller lips. The Kardashian's procedures were so obvious, the changes so extreme, and the money they made through simply wandering around and being photographed like that so insane, that they have effectively sold the idea that PS and beauty (by which we mean sexual desirability) and financial success (translate: happiness) are inextricably tied together to the youngest, most insecure and gullible demographic.
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