In a farming society fathers and mothers have a lot of meaningful expertise to pass down to their children. And they work closely with their children for decades. Family time is intense and probably not exactly utopian, but intimate and constructive.
As a father to a kid in the urbanized 20th and 21st century, way less well defined and the role super confusing. My kid is unlikely to do what I'm doing. I'm out of the house at work almost all day, and they're at school. My spouse and I would live relatively separate lives, convening only after work hours. What am I supposed to be teaching my son? Most values will come from society at large not from home. How do I relate to my spouse?
It's not surprising there's a general disintegration of the family. Conservatives want to blame it on liberal values and lack of religion, but this is complete nonsense. The economic model changed, and the point of both marriage and the family changed as well. Forcing religion on your kids or getting all freaked out about family values and abortion won't fix it. The economic foundation of the whole thing is gone.