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.
It absolutely depends on what you consider to be fashion. If it's how a particular person dresses and presents themselves, there are very substantial working class manifestations of such, especially within queer communities.
If you're talking about high fashion and brands, then yeah no shit, the entire point is that you're manufacturing something exclusive. But I have a lot of friends who've made far more money than they've spent from a hobby in branded fashion, so it isn't something that's simple.
You're just hyper focusing on all the wrong parts of these things rather than the broader thing at hand. Like there are tons of working class people who like to fix up old cars, but there are others who own 200k ferraris, it's still the same hobby.