IMO the tiny 1950's boxes were the start of the problem. "Everybody gets a house", yet it made for an extreme pressure for kids to gtfo as soon as possible rather than living in the bedroom across the hall from your parents (assuming the parents even allow that).

My grandparents had a bona fide two family house, two stories with the common "balloon" construction from the (earlier) period. Looking at how its use changed through the years, it allowed for great flexibility. Lots of bedrooms for kids, somewhat private space as they got into their teenage+ years. Then after most moved out and settled down on their own, one stayed in the upstairs apartment with their husband and own kid, and helped out grandma while grandma helped watch the next generation. Then when grandma passed, the house passed to a different brother, who lived in one apartment and rented out the second.

Now modern humongous homes are trying to recreate some of that flexibility, but not doing a great job at it. They're still focused on a singular living space where everyone has to interact with each other. This is often due to zoning regulations directly aimed at preventing people from creating full second living spaces that would be possible to rent on the open market - when it's exactly that independence that allows scaling how much house you're actually using.