It's been similar in the Bay Area since the 70s-80s. A common joke here in SF is "What's present are you getting your 4 year old? A house in Marin/Walnut Creek".

Also if we're being honest, SF was never the tech hub of the Bay Area - it was always Santa Clara County. Before the 2010s, the only major software company here in SF was probably Salesforce and that's because Benioff is a townie.