That is not necessarily true in CA. I've been trying to build a custom home since the beginning of covid, in SoCal. The state is quite intentionally making it tough for single fam. homes, with incentives for big projects that involve high density housing. The restrictions/requirements for single fam. houses is ridiculous.
We have the same thing up here in the Seattle Tacoma metro. No more subdivisions with just single detached. Apartments and townhouse style are the norm in order to boost density.
I have 120 homes going in on a lot of five acres across the street from me. By the time you plan in streets and sidewalks and required green areas the room for houses is condensed.