As a new landlord in San Francisco, I can tell you that the biggest issue forcing this is rent control. The way rent control works is certainly designed to help those in need but instead it creates a artificial demand for affordable housing. Without rent control, the market is free to compete and suddenly open up a ton of bottled up apartments. The issue is, a family on welfare with a income of 40k a year should not…
San Francisco is just one part of the Bay Area, and the Bay Area is just one part of California.
The entire state has high real estate prices, despite pockets of low-priced housing (Stockton, for example).
Law of supply and demand: a lot of people don't want to live in freezing Minneapolis or bleak Detroit. Or Mumbai or Monterrey, for that matter.
Rich or poor, they would rather be in place where there is a chance to bask in the sun by the ocean, even if requires an hour or two drive from their gritty neighborhood.