Just living in a place isn't really a good source.

Although you do make a decent point about safe housing. That's the reason why a lot of homeless people would actually prefer sleeping on the streets as opposed to shelters, which are often overcrowded, unsafe, dingy, and burdened with a lot of strict rules. The idea behind the Housing First model is to provide people with a single occupancy room, rather than cramping them together. This makes a bigger difference than you'd think.

This would imply that, to actually solve homelessness, we should prioritize getting people off the streets into safe housing, without first putting on drug quitting/rehab requirements. Something like putting housing...first?

Would be super cool to see the other boroughs too!