The increase in divorce reflects it becoming less of a stigma, and more economically viable, particularly for women. Before that, miserably unhappy couples simply stayed together - which isn't exactly optimal. Divorce is highly correlated with poverty for women, even today but this is much better than it used to be when pretty much all women were completely economically dependent on men.

People who got pregnant out of wedlock used to overwhelmingly get hitched in "shotgun weddings." Now, they don't feel the need to do that as often. So, pretty much what you are describing as positive was actually coercive, shaming, and restricting of freedom - particularly for women. I see the progressions of recent decades as being just that - not perfect, but still progress.