@TheBuffster
Interesting, but how many of those differences are necessary.
I offer two examples: firstly, we dress ds relatively gender neutral and pick from both girls and boys sections. However, it's becoming increasingly apparent that girls clothes are thin and poorly made compared to boys. Although the bright colours are tempting, economically and environmental wise we are better off going for boys as it lasts and is less flimsy. I'm pretty sure that it has nothing to do with sexed body difference and everything to do with capitalism.
Similarly with my clothes. DH clothes can withstand a tumble drying and hides his bumpy bits. Whereas even plain women's t shirts cling to every bump and curve. There's no practical reason for this and I understand some women might want figure hugging stuff but it seems to be the default, almost like we're obligated to 'set out our wares'.
I think most aren't necessary, for the most part they are stylistic though I think fast fashion doesn't impact so much on men's and boy's styles.
But in generally, I think people like to differentiate people by sex. There was some research a while ago that suggested that the more similar women's and men's lives were in terms of things like jobs, social roles, etc, the more people tend to emphasise differences in things like clothing.
There is something psychological there worth thinking about, it seems to me. Human beings noticed sexed bodies very readily, because it's so important to survival of the species. And maybe that also extends to us being interested in them, noting them, and so on.
I tend to think it is better to avoid separating men and women according to social role, even if it means accepting that people will play out their interest in sex through other cultural mediums. Clothes just aren't that important.