I should add, a very specific thing about the Bay Area that had an outsized contribution to my life was the group house culture. There are hundreds (or thousands?) of micro-communities sharing dwellings in the Bay in a way that's unlike anywhere else in the world, to my knowledge.

I've lived with men in their 60s in these contexts, but primarily this is an option for young people at the start of their careers, which I highly, highly recommend.

Any easy way to work on this problem is to simply lower the barriers to co-habitation. This could look like working to change zoning (I think Oregon has been a pioneer here), building businesses around the concept (many have tried, from small things you haven't heard of all the way up to WeWork), to experimental projects like: https://neighborhoodsf.com/Neighborhood+Notes/Published/The+....