Can’t speak for all women, but I (and I imagine some others) changed my name because I knew I’d be having kids and didn’t want there to be any confusion. Like, if I’m traveling internationally or if my kid ends up in the hospital, I don’t want one of us having to fish out a birth certificate to prove we’re both the parents. Also I’m of the percent that absolutely hated my long last name so the chance for my name to be shorter and nicer was a no brainer.