Eh, I really thing big tech is a feasible means to building wealth. Just don't confuse 'publicly traded' for 'big tech.' I understand the source of emotional pessimism, but wages for big tech seem to start around 200k, and increase annually with RSU refreshers.
It is entirely feasible to save away 100k a year in that scenario. Invested prudently, that'll compound up well with a far lower risk than the startup equity lottery, and is far more liquid. You don't even have to invest in real estate, if you're happy renting, and the current tax situation makes home ownership marginally less appealing.
The problem is that so is everyone else - or maybe not "everyone", but a significant enough fraction of the Bay Area to have a measurable impact on prices. So while I saved up a whole lot, most of it will get eaten up if we choose to buy a house in the area. The competition among homebuyers isn't your average middle-class professional, it's couples where both of them work at FAANG companies, making over half a million combined a year. When all buyers have the same means, prices rise to match, and you get inflation, you don't get wealth creation. The only way to get wealth creation is to build more wealth (in this case housing, but it also refers to other social services like childcare, healthcare, transportation infrastructure, etc.).
Right now, we're doing standard-of-living arbitrage: we live like people who don't (and didn't) work in tech, rent an apartment, and bank the rest, which gives me time to work on my startup idea (going for #1) and my wife a decent cushion to advance her career. That only works until what's left of the middle-class is entirely priced out of Silicon Valley, though. While immigrants and service workers can still find apartments, rents will remain priced at what they can afford, but if the housing crunch becomes severe enough that all of them move over the hill to Pleasanton or Davis (which is already happening to a lot of them), rents will jump to the maximum that a tech salary can afford.
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.