Communism

These prefab panel apartment buildings were made to reduce homelessness. Obviously, the people living in there weren't homeless anymore by that point, and in many cases they weren't homeless before either, because, believe or not, at the time, those apartments were a big upgrade for people from rural regions.

These brutalist style buildings were/are not very pretty, and I would much prefer the much nicer, organically grown mid-density residential areas of Western Europe, but if given the choice between solving the homelessness problem with anti-homeless spikes and police raids on tent cities versus solving it by constructing a lot more mid- to high- density apartment buildings of any type, pretty or not, I would definitely prefer the latter.