It
is the new normal if you look at crime statistics.
The insinuation that social workers can fix this problem or the problem is rooted in mental health issues is a problem.
These are, for the most part, grown men deciding to use violence for income (theft in various forms) or to settle disputes. I don't know what you think a social worker is going to do to diffuse a fight (not that they'd be notified and arrive before it was long over) or if anyone with that background would willingly put themselves in the middle of a potentially violent encounter and think they could make everybody play nice and use their words.
There is some magical thinking and somewhat offensive blaming of mental illness on crime.
And excluding yourself from certain populations is absolutely effective, and not "society" that you're shutting yourself off from. Unfortunately you do leave a lot of people behind trying to escape from crime, but there are plenty of effective ways of doing it, if you have the means.
Cities in the US are nothing like SA and the problems are nothing similar.