California is ruthless with its rent, gotta take that into account, many people in Los Angeles and San Francisco make 100k+ and still live with their parents.
Plus if California were to secede, it alone would be the world’s 6th or 7th largest economy, and is one of the few states that pays more tax to the Federal Government than it receives in subsidiaries, another rich state is Texas. States like Dakota, South Carolina or Montana don't have those kind of wages. California is a Tech/Resource/Tourism hub of the US economy, wages would reflect that.