I agree that that's the major problem; the poverty is inexcusable. But that's not caused by the $300B (or whatever) of equity. It's caused because the homeowners of the Bay Area decided that once they got a house, nobody else should, and that they should get to exclude others from the opportunities they had.
This same thing was observed during the Gold Rush in California in the 1800s; extreme wealth also resulted in extreme poverty. And there's a great way to solve this: tax the land and redistribute it equally to everyone. Land can't be moved, it's something that belongs to all of us, and you can't make more of it.
You sort of can make more land -- by building tall buildings. Unfortunately the Bay Area has mostly outlawed that, too. And we can't blame that just on homeowners. SF "tenant advocates" are just as violently allergic to developers building new structures as homeowners are. But the worst offenders are definitely Peninsula and South Bay homeowners.
That distinction between tall buildings and shorter buildings on the same plot of land is exactly why the land should be taxed.
Economic land is any capital that has a fixed amount, that you can't make more of. When the local governments in the Bay Area started capping the amount of buildable square feet, they greatly accelerated inequality by converting regular living space and working space into economic land, just like the real land it sits upon.
This is why economic inequality skyrocketed so much. Rentierism resulted in so much being stolen from anybody who doesn't own the land, and blocks out so many people from even having access to the economic system.