Why on Earth would anyone want to tamper with their God given bumpers?
I cannot understand why someone would want a surgical procedure for cosmetic reasons..
And where will the surgical procedures stop? A nose job, an eye job, horns on the head?

When flat chested there are no bumpers...
To me the reason would be if I'd be very unhappy with small/no boobs.
I can imagine not feeling very feminine. If I'd be flat chested I'm quite sure I would've gone for implants. Not for anyone else, just for my own sense of well-being and feeling like a woman.
The way I see it any cosmetic surgery should be about someone's own sense of well-being.
Not to please anyone else, nor to fit a fashion thing.
I get what you're saying - but I don't think it's boobs that give the feminine energy. That's exactly why a dude can't slap a pair of boobs on himself and call himself a woman
You do't understand cos you're not a woman, hihi.
If having breasts -even non-natural ones- makes you feel great and more like a woman it will boost her self-worth, self-confidence, self-love etc. etc.
And with that it will also give her an incredible increase in oestrogen... Not the breast themselves as they're not natural but the side-effect of what I mentioned above will do the trick.
And again: if a woman is perfectly happy with small breasts or barely any/no breasts there's nothing wrong with that and no reason whatsoever to have this altered surgically.
Most certainly not because of a hype or any 3rd party demands.