> London, Tokyo, New York and pretty much every other major metropolis has problems akin to the Bay Area

I've never lived in the Bay Area/SF so I can't comment on the problems there, but I have lived in London for the past few years.

I volunteer extensively with the homeless, and I haven't seen a fraction of what people describe in San Francisco, or anywhere near the level of antisocial behaviour or crime. Every week I'm serving food on the streets for at least a few hours; I've never once been threatened with anything other than words (and even then maybe twice with words?), never seen needles lying around (co-volunteers have, not common though), and never seen human faeces on the street.