Don't underestimate the possibility of a death spiral. It's already happened once. Read Gray Brechin's excellent book Imperial San Francisco. SF used to be the undisputed capital of the entire North American West Coast, and arguably even the entire Pacific. In the aftermath of the 1906 earthquake, it lost that position to LA.

I lived in SF for 19 years, moved to London (family reasons, elderly parents with health issues) and are planning to return to the US. My wife put an absolute veto on returning to SF itself because of how dire the law and order situation has become.

Sad to say, but the city really needs a 1990s vintage Rudy Giuliani to clean house. Otherwise what it will get is Bernie Goetz (yes, I know, I am showing my age with my references). It seems unthinkable today, but in the 1950s and 60s SF was actually a fairly right-wing city, all mayors from 1912 to 1964 were Republicans.