I think you’re high

Well if you look at the outfits wrestlers like the big show wear they look a little like swimsuits.... as for why women don't just wear trunks... boobs

The same reason you don’t wear socks on ur hands...

I dunno

Oh good question...

Because we live in a patriarchal society that chastises women who don't cover up but often encourages male bravado and ego.

Ask the people who created the law

Well back in the time they actually did and some swimmers still do...for women I think that’s an obvious reason...lol