But it's a conspiracy theory that doesn't even require a explicit coordination, just people acting in their own self interest.
Also they understand that most of these companies are 100% losses anyway, but real estate investments are much less likely to go to zero. (Plus rent is just cold hard cash.)
I never said that's the only reason it exists, but you know what, that might be the only reason it's so hyper localized to one place.
Let's look at the incentives:
Pretend you are a wealthy VC with tens of millions invested in San Francisco real estate.
You have been given billions by LPs to manage.
If I, as the person that has control over how this money can be distributed, only invest those billions in the bay area and bring all these high skilled workers to this one place I can actually impact the price of real estate and triple the tens of millions I already have invested. Once those high skill workers move here they will remain, even after the initial startup goes under because they will move to a different startup.
Now if all the VCs are doing this and they all control large multi billion dollar funds...