I'm in LA now, and "Silicon Beach" in Venice and Santa Monica is an utter joke compared to the entire Bay Area. Silicon beach is a few square blocks, whereas the entire Bay Area is awash in tech, no matter where you go.
Silicon Valley is entirely geared around tech. You can find anything and anyone there.
It is the same as Los Angeles to movies. You can't beat LA, because they have been doing it 100 years and have a zillion companies backing it up - all the little companies. There are oodles of movie industry lawyers, talent agencies, accounting firms, all geared to specifically the film industry. Are you going to be able to find 10 law firms in Silicon Valley or Chicago or Miami that deal exclusively in the entertainment industry? No.