I’m sure SF proper is far more resilient than near every place in the US (probably more than NY too due to low number of wall street types)….
Manhattan is extremely resilient because most apartments are co-ops and they require 10-20% (or more in case of insane buildings) down. A small % are condos and houses, the rest are multi-family buildings which are typically owned by investors wanting to make money. Either bought with cash or mortgaged in a way that makes sense, since banks wouldn’t finance a losing proposition.
Wall Street types are actually not as large of a % of owners as you might imagine.