Probably some sort of self selection bias.
We still have wars, men are still more muscular than females.
Men are better protectors, generally speaking.
Females have all the body parts the enable them to raise children, more effectively.
They typically should be the primary care giver.
That is until men start growing breasts and lactate when their children are born.
Organic change guides itself, it's the "Adam Smith" type of evolution that has made humans so successful, in the first place.
Little "know it alls" that think the world should be how they want it, aren't able to actually make wide spread constructive changes because of information asymmetry.