It's mostly because the political culture of SF is trying to solve a mental health issue in compromising way, because the real solution set is not a local level thing, but a state and federal level thing. It's same with the current DA, trying to activist create an alternative to arrest vs. using social workers, while such a solution needs more than the power of the DA's office to properly implement. So you get half-assed solutions that don't actually solve anything much.
Also pure corruption. You'll notice there are a bunch of regions where the homeless roam, and bunch where they do not, and there are very good reasons as to why that is the case.
> the homeless in Uzhhorod starve to death or freeze in winter
I doubt it. Housing is one of those problems that is quite easy to solve and the fact that poorer countries can do it while the US can't must be because of nefarious. The same shit is said about developing countries having a lower COVID death rate than the US, "they must be hiding a lot of bodies." In fact, it is quite hard to hide a lot of bodies.
The fact is the US does poorly on a lot of metrics and we have the capability not to.