I believe divorces are declining, but that's because there's fewer marriages. Marriage rates are very high and divorce rates very low among the top 20% of Americans. Rather interesting.
British social surveys have shown that women were happier in the 1950s than today. Which is also interesting. I do think more women responded positively to strong cultural norms ordaining the nuclear family structure with breadwinning father and housewife raising children. They liked the cultural and social structure provided by that society. Same for men, too. Sure, there were unhappy marriages back then but we are focusing on the aggregate, not individual cases. The anything goes outlook of today's world has resulted in clear winners among a minority of women but for most women it's probably been a net loss rather than gain.