Ditch Social Security.
A good start.
I see the obstacle to the extended family as one of space in the house, AND desire. It is difficult to have mother/father in the same house as you are on the prowl for either "good time"s or husband/wife number "X".
I see too much sick humor about being nice to your kids because they pick your nursing home. I have also personally seen the nightmarish nursing homes, not good for animals let alone humans.
Of course if a builder was REALLY smare they would start building homes with TWO or THREE masters suites. (iow each with seperate bathroom and REALLY good soundproofing.)