You know what--in reality--has done more to undermine family? Especially extended family?
Corporate models requiring a mobile workforce along with the downward mobility of the working class.
If you want to buy a house, want to earn enough to support a family, then a significant segment of the population has to get a college education and then go to work for a large company that may spin off divisions, merge with other companies, etc, and then force its workforce to relocate.