I don’t know if it’s a generational thing. I think there is a cultural thing.
Specifically, Americans, post WWII, wanted the house, car, suburban lifestyle. Other countries didn’t make that same change. My husbands relatives in Italy are all professional, upper middle class types… and all have large apartments or what we might call town houses (party walls with the adjacent neighbors.) The single family home is just not common in that culture.
These folks have kids, grandkids, etc… They never felt the need to get a single family home in the suburbs. It wasn’t part of their culture. It wasn’t that they couldn’t afford it – like I said, they’re all highly educated, upper middle class folks.
In most other countries (except perhaps Canada) – apartment/condo living is perfectly acceptable. Even for people with kids.