> I've seen it argued that, paradoxically, the richer and more egalitarian a society is,

The former-Communist East-European country I lived in as a kid was a lot more egalitarian than most of present-day Western countries and the women were treated pretty much the same as men were when it came to work. I remember as a kid that I regarded my mother going each morning to work and returning in the evening as a very normal thing, and I regarded the few kids' mothers who weren't doing that as being lazy (to this day I still think that a stay-at-home parent is a lazy human being).

State-run kindergartens were also of much help for women back then.