It's the killer of public transit everywhere. The ability to avoid such people is a huge benefit of individual transportation. Nobody sane wants to be subjected to stuff like that. Anyone saying otherwise is virtue signalling.
I’d argue not everywhere, it just requires a critical mass of “normal” (anti-anti-social?) people to use it.
Like in NYC. Most assuredly there are anti social people on the subway but they’re a tiny minority of overall passengers so people still use the system. But it’s a self-reinforcing thing that has danger of collapse, the more people drop off the more the ratio will change… and more will drop off.
In many places it's just not a big enough problem. And, either way, it's a perception issue usually.
I mean yeah, subway homeless people make you feel unsafe. But you're not actually unsafe. Just by taking the subway you're a few orders of magnitude less likely to die during your journey.