Oh, I cross-posted with YKK. Well, I was being cheeky in my initial post, but I'll say that I am not sure that I agree that the obligate display of the body -- particularly the female body -- is necessarily progressive.
To be a little less theoretical about it, I don't think that *everyone* is necessarily covering up nowadays out of prudery. I think there are just more choices for swimwear and some people are choosing more covered options for a variety of reasons, not necessarily a return to conservative mores.
It's true, I used to look at pics of people in those heavy wool 1920s bathing costumes and think: ugh, how repressive. I never questioned the prevailing norms for female swimwear and yes, probably considered them to represent progress.
This year, I looked around and noticed various forms of gender-neutral swimwear available and thought: hey, I might want something like that. Why should I have to put my whole body on display and constantly pick lycra out of my butt crack just because my pronouns are she/her? I bought a pair of running short-style swim bottoms and a couple of sleeveless rash guard-type tops for our recent vacation and was very happy wearing them.
I think it's great that nude beaches exist (not so great that they are in wild boar habitat, maybe!). I think it's great that women of all ages and body shapes wear bikinis. (Maybe I'll do so in the future!) I think it's great that people can choose more covered styles if they want.
