Well, I can't back this up with hard numbers at this point, but I'm pretty sure that the SF Bay Area has lead the nation in hiring since 2008. Also, where else in the US are you hearing about people becoming rich beyond their wildest dreams? Or about how a new company IPOing will bring about 1000 millionaires? I dont see it anywhere else
Granted, I think it's more accurate to say that "tech" is the one doing the hiring and making people rich, not the SF Bay Area itself. But since this is the nexus of the (consumer internet) tech industry worldwide, I think its safe to say that a lot of that opportunity is found here