> I'd wager that astronomical housing costs are the biggest factor in these absurd salaries, followed by healthcare.
The causal relationship is in the opposite direction: high salaries cause high housing costs. Law of rent gives a theoretical explanation of this, but we can see this empirically too: rents go up in cities after tech companies with high salaries start opening up offices there, not before. There are also plenty of places with low rent that have higher tech salaries than places with higher rents (compare essentially any US city to Toronto).
> In the end it's a circle of money, from investors to mega-companies to their employees to their landlords which are again part of the investor class.
At least in California, there's not that much overlap between tech company investors and landowners. The housing ownership is much more distributed, and often to "mom and pop" landlords. This is the flow of money in Silicon Valley (expressed in a slightly comic manner): https://twitter.com/nextdoorsv/status/1400165321609199620
It's a bit different in other locations with more consolidation in land ownership, but even there, I doubt there's much overlap (I have less knowledge of housing dynamics outside California, because they actually change, so I'm just guessing here).