I'm flat as a crepe when I bind but many men's button down shirts still don't fit me because the hips are too narrow. It's not like I have wide hips either, I'm under 100cm at the widest point of my butt, but if they fit me in the shoulders, they don't fit me in the hips. I can't wear women's button downs either because the chests are always too big and most of them insist on skipping the button between the neck and chest so the wearer has to show cleavage. Ugh. Little gendered things like that in sizing and construction are really bothersome when you fall outside of the binary.