If you're asking this seriously... yes it is a barrier, but not as great as Immigration/moving to a completely new country.

Which is not to discount California's tremendous housing crunch. I am merely pointing out that its a much lower risk for a young single US citizen to just move to CA, try it out for a few months, if they can't get a job or make it, then just drive back. It is much harder for people from outside the country to do the same.

Not really. The cost of housing is huge and a barrier if you are not in tech, But if you move for tech you can definitely find a place and pay the crazy rent with your new salary.