I live in Boston, which is a similar size and population to SF, and it's extremely safe. There is some crime but even something minor like porch pirates are pretty much not a thing. There is a skid row named "Mass and Cass" which has had HBO documentaries made about it, but there are a lot of protests from citizens advocating to clean it up.

At some point you need the police to arrest all these people and throw them in jail. Even a few weeks behind bars can drastically improve behavior among a population used to zero consequences for theft and violence.