when it comes up against something like the mythical wage gap
That's not something mythical, it's a fact. Everything you mention has of course been accounted for in the countless of studies done on the subject. All those things like making it a bit cooler for men to take care of kids etc. does help women earn more money but not enough to close the gap. So the simple statistic on how much money you get per hour or year, is surprisingly effective even with all those factors in there.