All those startups are pumping insane amounts of money into the entire region of the SF bay area, to the exclusion of nearly all other locations - no matter what, it will massively effect the economy of the bay area.
I'm not convinced though that the money being pumped in by those startups (as opposed to the big tech companies that are making money) are of the same order as when the first thing any startup did was to buy a few $M worth of proprietary hardware.