Very rapid modern development (basements are expensive and take a lot of time), no tornados to worry about, no need to have a dry dark place to store stuff through the winter. Also foundations/supports need to extend below the frostline, so in cold climates you might as well add a whole basement if you’re gonna be digging deep anyway. In CA that’s not an issue.
“California basements” are actually becoming more common, and are tiny basements purely to put pipes and appliances and stuff that would take up valuable space in the main part of the house.
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