There are more households now, there are some stats in this thread. There are also fewer houses, apparently.

But yeah, there is a general trend whereby neighborhoods that lots of people moved in 30-40 years ago are largely inhabited by older folks. Usually these places were in locations close to cities that became more desirable in the last 20 years, increasing their housing values. The kids of these home owners can't afford a house in the same area, so they move away.

It's a sad cycle that leads to both the parents and the kids more isolated because no one can afford to live near each other.