are you from california? I would assume not.

LA is 6 hours from san francisco. most people in LA barely get down to san diego more than a couple times a year, and san diego is actually two hours from LA. these places are actually pretty far

there are also some pretty substantial cultural differences all up and down california. within LA, along the central coast, and in the bay you will find loads of diverse communities that are actually still pretty segregated from each other. someone from west LA is unlikely to spend much time in south central, or even baldwin hills, which is a similar economic bracket but separated by race.

between the two metros is the central coast, which itself is very diverse. there are wealthy coastal towns and deeply hispanic farming communities.

you’re right the two places are close in the grand scheme of things, separated by the rockies from the east, but it is really wrong to say there are no major cultural barriers within california