Salaries yes, stock compensation not necessarily. It's very rare to cut salaries because you end up demoralizing employees, who then aren't productive, so why bother to pay them anything? That's why companies do layoffs, where they just eliminate jobs rather than pay less.

Keep in mind that when everybody gets paid a lot, everything is expensive. That's the real way that high salaries return to the norm: everything else catches up. Bay Area is already the most expensive part of the U.S; you might get paid $200-300K, but taxes eat half that, rents are $2.5-3K/month, mortgage payments are $10K+, daycare is about $2-3K, restaurant meals are $30, etc.

Not sure how that compares to your country - if you're coming from Eastern Europe you're going to get sticker shock, but a lot of central/western European regions (eg. Zurich, Paris, Scandinavia) are already there. It's a different type of expensive though: in general consumer goods, food, housing, and gas cost more in Europe, but healthcare, education, and childcare cost more in the U.S.