The first place to look is suburban development.
I wrote an article[0] on Tiny Neighborhoods (aka “Cohousing”) that starts with:
> “I often wonder if the standard approach to housing is the best we can do. About 70% of Americans live in a suburb, which means that this design pattern affects our lives – where we shop, how we eat, who we know – more than any other part of modern life.”
We have been so uncritical of the set of ideas that make suburbia—single family homes, one car per adult, large private yards—even though these play a big role in how people act.
Some people want to address loneliness by making incremental changes. But if the statistics are right and nearly everyone is somewhat lonely, we should expect that the required adjustments feel “drastic” compared to the current norm.
People would be less lonely if they could live in a community of 15-20 families with (1) shared space and (2) shared expectations for working together on their shared space.
I posted on another subthread but I think this is largely an excuse. If you live in a typical suburb you have 15-20 families on your street. You can easily walk next door and chat or just say hello when you see someone outside. It takes initiative, which is the key thing that's missing. You either hide in your house or you get out and be sociable.