I only know what I know so prove me wrong. I think almost all other forms of art, from music to television and cinema to sculpture and mixed media and painting to dance all have proletarian channels, but fashion is almost exclusively for the wealthy. Arguably also it seems to me that a lot of culinary art tends to cater to the wealthy too, so fuck that as well.
i don't think fashion has to be bourgeois. I think people choosing their own styles is cool and good. Maybe a prole fashion show would be things people modified/created themselves. The problems with fashion i see are these:
Price. Most clothes are either way too cheap because they're made with slave labor, or way overpriced because rich people are easy marks. Ideally basic clothing would be free and made by union workers and relatively environmentally safe dyes/materials
Style over Utilty. Anyone who has looked at women's clothes knows this to be true. There are no fucking pockets anywhere, or they cost like $100 if they have actually decent pockets. I've yet to meet someone who wears women's clothes that likes the lacks of pockets. Just sew some dang pockets in. And clothes should mostly be baseline comfortable to wear and not restrictive. That's not even getting into the horror show that is women's shoes. Heels are not comfortable, at most you adapt to them and stop being quite as uncomfortable.
We live in a Society. A society that sucks and is bad and likes to put unrealistic expectations on people but also expects them to conform even when they literally can't. If you're talking about the problems of the fashion industry you can't leave out all how them choosing only thin white models is giving people eating disorders and self-esteem problems. That shit just isn't realistic. We need diverse models, in sizing and body type, skin color etc because that just makes the most sense if your goal is to show people how clothing looks on the general populace. And to discard all the arbitrary rules about which gender is allowed to wear what and how black people must do their hair etc.
Anyway, in a post-scarcity socialist world, i'm sure fashion would still exist because there is an art to it and artists gonna art, and humans gonna self-express. It'll hopefully be wildly different than the bourgeois fashion world of today, that you need to be rich to participate in.