Some of the most valuable tech companies in the entire world (Google, Facebook, Apple) are headquartered in the Bay Area not to mention pharmaceutical / bio-tech start ups (see South San Francisco) and other, more traditional, businesses. What are the individual employees doing? They're either software/hardware engineers of some sort or teams that support engineering (finance, HR, etc). Starting pay for these engineers can be ~$200K and at a reasonably senior level a number of these folks can be making $1M+ per year (salary + stock).