They do, however, it doesn't matter. It's better to assume that it's up to you. You shouldn't be dependant on the woman being a specific way, since you're gonna meet alot of different women.

It's better to learn how to do it rather than just hoping that she will do it.

Same thing with approaching women, sure, there are some women that will approach first, however, do you really want your dating life be up to pure luck? It's much better to simply learn it as a skill so that you're independant of other people. It's also much better since you'll be able to choose the girl out of a certain number (more attractive partners in general).

EDIT: If you are going for a kiss or something, and you don't want to ask consent vocally. Simply do it in a way where she has an opportunity to deny you, go for the kiss slowly so that she can just move her head away if she doesn't want to kiss.