YMMV is right. There's a lot of factors here. It's almost meaningless to take averages without qualifying those against a fairly large number of conditions.
Total comp North of 300K for an IC sounds like science fiction to many folks which aren't in Silicon Valley, in certain fields, and in certain companies.
“compensation” is something I can trade for cash once I have earned it and then exchange for good and services.
Besides that, it takes the average startup 7-10 years to exit. As opposed to a public company where you can diversify your risk every three to six months depending on your vesting schedule.
Looking at a few non-SV cities such as Seattle, Chicago, Nashville, Orlando, Sacramento, Austin, and Fresno it costs $14-18k/year more to rent a 1 bedroom apartment in the Bay Area than to rent in those other places.
The average monthly spending on food in SF is about $150/month more than the US average. That's under $2K/year.
California does have a high income tax. For someone moving from somewhere else to California you might have to pay them maybe 10% more to compensate for that.
Putting it all together, a job that pays around $100k/year in non-SV non-NY decent sized cities should need to pay if we are generous maybe around $140k/year due to higher COL in the Bay Area.
That Bay Area tech pay is way more than that suggests that something other than SV COL is the main factor.
People are saying $350k remote jobs don't exist. Which obviously is untrue (go work at Airbnb). But they're exceedingly rare.