"Having made the opposite move for a big tech job, the headwinds here against upward mobility are really striking."
CA (at least the Bay Area) incentivizes a very different sort of upward mobility: striking it rich through owning equity in a business doing fundamental innovation in its area.
If you're hoping to steadily build wealth by working for a big tech company, staying in CA long-term, and saving your money, you're playing the wrong game. (And I say this as someone who came to CA to work at a big tech company, has been here a decade, and married a local.) There are three basic paths to wealth in Silicon Valley:
1. Found a company outside of the valley. Do all the initial work in a low-CoL area, get customers and traction there, and then move to Silicon Valley for fundraising and scaling. Enjoy your equity appreciation, and cash out a billionaire.
2. Move here in your 20s. Get on a rocketship - a company that is likely to go public in the next 5 years. Stick it out for 5-ish years, enjoy your equity appreciation, and cash out a millionaire. Move to some other low-CoL area to buy a house and retire.
3. Get a time machine. Buy a house 15 years ago. Enjoy your equity appreciation as successive waves of #1 and #2 bid up housing prices. Cash out now, and move to some other low-CoL area to retire.
If you're moving here hoping to work for one company the rest of your life, save up, and eventually own a home, you're in for a rude shock. Most of the housing stock is taken up by #3, and #1 and #2 will be able to bid up the rest far higher than any ordinary worker can afford without using a perilously high proportion of their salary. If there's a market downturn or shift in the tech industry, you get laid off, your employer's stock takes a hit, and you're screwed because many lenders count stock compensation as part of your income for deciding how much mortgage to give you. And housing prices in Silicon Valley are heavily correlated to the fortunes of the tech industry, so if there's ever a permanent downturn, this place will be the next Detroit.