A Security Engineering Manager at Google thinks so:
Top tech talent that is already in the Bay Area is pretty much guaranteed to be in a great role already. People do change jobs occasionally but basically the talent pool is tapped out. So that means recruiting someone from outside. You know what makes a crappy recruiting pitch? 10% income tax, $3000/month rent for 1 bedroom, and 90 minute commutes. California's restrictions on guns are also a deal breaker for a nontrivial number of people. When you can live in Seattle instead and work for an equally good company with no income tax, $2000 rents and 30 minutes commutes, the Bay Area looks like a terrible deal. This is a big reason , growing 3 times faster than San Francisco, and why Google is expanding faster outside the Bay Area than inside it.