Economics

It's worth remembering that once you get to the street, you now live in a combat zone that will cause PTSD along with a host of other psychological issues.

Housing first initiatives are the cheapest option we have. Once society stops creating new psychological disorders in their homeless population, then the formerly homeless can move out of survival mode, and actually address their many other problems*.

*Provided of course that one can actually afford to thrive on a single income regardless of the job one takes.