answer:Mostly arbitrary fashion history, I expect. The pocket thing is a current practical issue. Women’s fashion emphasizes shaming fat and trying for competitions of thin-ness, and so big useful pockets are generally not put on women’s clothes. Often they just have the appearance of pockets but no pocket, to make them appear slimmer. So where to put a coin-purse, yet minimize apparent body bulk? Why, a bag. The makeup focus is probably also a reason. Other feminine products too, but even if that weren’t an issue, the others would I think suffice.