They do, at least for earthquake insurance: https://www.earthquakeauthority.com/ https://www.earthquakeauthority.com/ CA has required since the 80s that insure

They do, at least for earthquake insurance: https://www.earthquakeauthority.com/ https://www.earthquakeauthority.com/ CA has required since the 80s that insurers that offer homeowner insurance also offer earthquake. However, after the ‘94 Northridge earthquake, 93% of insurers had either stopped offering or greatly restricted their property insurance underwriting in CA. Now the CEA sells two thirds of the earthquake insurance policies in CA. So if the insurance companies don’t step up and underwrite, CA may very well do just what you said.