So, I left SV in 1992 (when "Silicon Valley" meant the south Bay, not SF), and at that time it was because, as a single guy with no dependents and an engineer's salary, I was barely scraping by due to high cost of living. In 1992. San Francisco was, even then, worse than south Bay in this respect.

So, yes, SV (especially SF) is clearly unsustainable. As the saying goes, "that which cannot go on forever, won't". But, you know, it's been 28 years since then, so I have stopped trying to predict when it stops getting more expensive faster than inflation, and crashes instead. Someday, it will happen. Perhaps this is the day. But, you know, I've thought that before.