And it seems likely that this novel and rapid change was brought about by women, for the first time in history, being protected from violence and abuse, and thus free to express desires for greater equality and liberties that most women throughout history secretly always wanted. IOW, criminalization of some of the more extreme forms of "toxic masculinity" allowed women to finally enjoy more of the benefits of civilized society where violent brute force is not given free reign to determine who comes out on top. A related factor is women in the workforce which allowed the to escape from being under control of their mates, which itself is partly a byproduct of their mates not being allowed to physically prevent them from working, but also sparked by need for more workers during WW I and II.
Yeah it was probably lots of things. But one of the big ones was women, in large numbers, organising for change.
I was not aware that this was preceded, as you imply, by criminalisation of things which kept women down, but you may know better than me.
I think you're more aware than you know. I am mostly just referring to husbands not being able to beat their wives with as much impunity (not just changes to formal law but changes in enforcement such that cops no longer disregard domestic abuse), parents not being able to beat their kids (which is used to enforce authoritarian cultural norms, including women's "proper place"), and changes in the law allowing women to vote. IOW, I think women would have organized for change much sooner and would do so everywhere if the law gave them voting power to effect change and protection from retaliation when they attempt to create it.
In turn, all of these things were eventual byproducts of the principles of personal liberty that arose from the Enlightenment. The US Constitution and Bill of Rights didn't grant these basic protections to women and blacks, but did establish core principles of secular, non-authoritarian law that laid the foundation for those rights to gradually expand to all people, because there is no reasoned basis to oppose that expansion that doesn't contradict the principle itself with grants those rights to those who already enjoy them.
When you look at the countries today with the greatest inequality of rights and strongest enforced gender norms, they are places (mostly Islamic countries) where women lack basic human rights and are not are not protected by the state from physical harm by their mates and families, thus they cannot organize for real change.
In sum, basic rights to free from violent coercion from other members of society, including one's own mate and family, are essential for people to be able to have the freedom needed to organize to fight for additional rights, and to lessen cultural norms designed to enforce inequalities.