1) "Rich people" want their property values to be stable or increase. They want their communities to be somewhat static. If I paid $1MM+ for a property in a dense CA metro, I can't say that'd I'd disagree with those desires. I'm buying a home and a location, not "housing" as a commodity.

2) Tech companies unnecessarily demand butts in chairs in the Bay Area, foisting the externalities onto the commons (infrastructure and housing). Tax them more if they won't go remote/support remote work. Destroy demand for dense housing and the associated infrastructure.

3) It's documented that there's substantial Chinese money flowing into specific US markets (the US isn't alone of course; Canada, Australia, and the UK also have this problem). This pushes up the price of real estate, whether these properties are lived in or simply used as a store of value outside of the CCP's reach.

Due to property owner/voter and governance momentum, it is unlikely you will see the will to increase development inertia in any California market that requires it, ever. Your options are to complain and put up with it, find an economic path to leaping onto the ownership ladder ("startup lottery", inheritance, etc), or eventually abandoning hope and moving somewhere cheaper/more development friendly (such as Colorado, Texas, Utah, Tennessee, North Carolina, Florida, etc).

Disclaimer: Not a CA resident, too expensive!