like in theory yeah, but in wider society they do, and gendering is not only something we do to ourselves, but also something that is done to us. i can get whatever hair cut i want and still consider myself a woman, but to wider society, that will influence how i am perceived and categorized.
I’d say that’s a bad-faith argument coming from a transphobe the vast majority of the time. Anyone with any sense understands that clothes/haircuts/whatever don’t **have to be** gendered (aka anyone of any gender can and should do whatever tf they want) and also understands that those things can be and often are gendered by greater society (and, as such, can be gender affirming or cause dysphoria)