Bingo. And why not?
The Bay Area's population has grown by 8.5% in the last 10 years. [0] Please, that's not "Manhattan". That's one person on your block converting their garage into a rentable unit.
Those "existing homeowners" are really messing things up for everyone because they don't want Bob to turn his garage into a rental? Somehow I think there's more to it than that.
[0]: https://www.kqed.org/news/11741275/map-the-bay-area-leads-ca...
600k people is about as much as Seattle proper. Which happens to span 83.94 sq mi. In less than 10 years. That's _a lot_ of construction.
Of course I wouldn't mind becoming more like Manhattan in some ways. Compared to how pedestrian hostile the Bay Area is, Manhattan is heaven.
Because California property owners don't want it to. The artificial scarcity drives up property values. Take a look at Brisbane, they fought residential development tooth and nail claiming that people should just work in Brisbane but live in San Francisco.