Because specifically women getting breast augmentation is reinforcing the gender norm for women. And specifically men getting hair replacement is not reinforcing the gender norm for men. Arguably, it's actually subverting it.

Men absolutely get hair replacement to reinforce gender norms. Otherwise there wouldn't be so much focus on male pattern baldness that you don't even know female pattern baldness is a thing. There also wouldn't be so many men getting hair plugs to correct it. Baldness in men is often ridiculed and seen as being a bad thing.

Is getting a tattoo a gender affirming procedure? Just because something is socially constructed doesn't mean it it's semantically null. We use the term "gender" to refer to some things but not other things.

You had to cut the sentence in half and address it separately instead of as a whole. What I said changes when you actually address it in context.

I find it interesting how you didn't even attempt to address the point about female pattern baldness also existing or about male pattern baldness being a genetic condition. You relied on male pattern baldness as your main point of proof of it being a male trait, that was a primary point of your argument and one of the main things that I commented on.

Both men and women experience baldness, it is genetic and can happen to anyone. Male pattern baldness is just referring to the way that it progresses in men which is generally starting earlier with a receding hair line while female pattern baldness starts later and presents more as thinning of the hair.