California’s housing issues are caused by uniquely California legal issues, some of which were good ideas at the time. Infill development can use advocates everywhere, but nowhere has such demand and yet so much opposition.

Not really. There are plenty of other quickly growing cities that aren't filled with NIMBYs destroying the housing stock (e.g. Phoenix, Indianapolis, Dallas, San Antonio, Las Vegas, etc).

Those cities are at different margins away from fundamental constraints. Because of geography, SF and SV were sort of locked into smaller footprints vs commute distances. Seattle/LA is just behind that with a bigger sprawl/commute margin but they're close to some limit at which property values spike up. Those other cities you name are wider flatter areas, with similarly wider margins, but they might hit other constraints soon... water for some of them. After they hit the constraint, their property values will spike too.

Yes, the weak and the old are usually the first to fall when an epidemic strikes