What makes homelessness complicated as a problem? It seems like there are many straightforward solutions to it from a government policy perspective - pairing rent control with welfare, building more housing tenements, and in general building out a social safety net. In what way are these solutions insufficient?

Homelessness is not a single problem but a manifestation of at least half a dozen different underlying problems, including mental illness, substance abuse, housing policy, and personal choices. It's very, very complicated.

Source: I spent four years hanging out with homeless people and made a documentary film about the experience:

http://graceofgodmovie.com/

Many people on the street have mental health issues. Yes, just having more housing would go a long way, but many choose to live on the street rather than deal with rules about drugs or caring for the housing.

Also rent control keeps the lucky few in their home, but doesn’t get people off the street.

Doesn’t seem that thought provoking. Winning chess tournaments isn’t a scalable solution to any problem.

I think what struck me was the juxtaposition of how well it worked as a solution for Tani's situation, compared to how poorly it would work in general.

No one would be surprised to hear that this solution doesn't scale, but the thoughts that it provokes in me are questions like "How does society produce outcomes that are nearly as good, but which can help more than just one person?"

Often there is an 80:20 approach, or the hard part is going from helping zero people to helping one person, but there doesn't seem like there's any way to adapt the success here to other instances of the same problem.

In fact, the magnitude of the success here could even be a distraction from more scalable solutions, either because people think that all such stories must have a happy ending, or that the only people who deserve such a positive outcome are those who are lucky enough to have rare talents.