Why don't we need it? I wouldn't mind being in the 0.1% or 0.0001% of earners in a place.

Sure, who doesn't want unlimited money? That's decidedly different from "needing" it (I could in no way manage to live on the West Coast on a Spanish salary, for example)

Well then why do the people who do earn that much there need it?

Sky-high cost of living (property prices, mostly). Shitty apartment with a commute in the bay costs $3,000/month. Starter home in Seattle costs a million plus.

It's also a vicious cycle: high tech salaries in those areas have driven up the cost of living.

> Shitty apartment with a commute in the bay costs $3,000/month. Starter home in Seattle costs a million plus.

The prices in Madrid/Barcelona are not exactly far off already (through no fault of high tech salaries).