California had a population of 10m in 1950, and 40m today. So presumably some housing was built. In that period California added the GDP of a mid sized European economy. Such a disaster.

Here's a chart showing California housing production. It's a pretty big failure over the past 15 years or so:

https://bendyimby.com/2018/11/03/california/

Plenty of houses in Detroit.

This isn’t really the root of the problem through. The government can’t get more housing through because the voters don’t want it, the voters don’t want it because the traffic is already bad enough and there is nowhere to build more roads, and they don’t consider taking the bus or funding more public transit. And even if you climb that hump you become New York City or Shanghai, both of which are plenty dense with public transit but still not affordable at all.

Seriously, without Singapore-style public housing, you just aren’t going to solve this problem in any reasonable way. But that would ruin housing as a good investment outside of a small niche market at the super high end.

Californians did themselves no favors by shooting themselves in the foot with Prop 13. Normally localities would fund more services for growing populations by reaping the benefits of higher assessments.