The problem is that once you start going down the rabbit hole towards that type of primitivism, you put everything in modern society up for grabs. Soon you're questioning why did we get rid of slavery, I mean, it worked so well for so long...
We *know*, on an intellectual level, that not everyone is actually equal. We also know on an intellectual level that societies that treat everyone as basically equal, even though we know they're not, work a whole lot better and progress a whole lot faster than the ones that don't, and certainly better than all the ones that didn't, historically.
Specifically on the point of the first part of the documentary, professions have stayed relatively gender specific largely because of mentorship. Men frequently don't stay in fields where they don't see a lot of male mentors early on in college, and females don't stay in fields where they don't find female mentors.