...the principal driver of high rates of homelessness is simply not enough (affordable) housing."
Way too simplistic. In a great many parts of the country, *anybody* who is able to get a job and actually show up and do it, can afford rent. If your ability to earn money is out of wack with rent where you are, then you can move. This has been the norm as long as I've been alive, and probably forever.
The housing cost vs wages "issue" is something that is naturally solved by the market. If the companies cannot hire cheap labor, then they will need to raise wages, or the housing cost will need to decline. Else the company will need to move or cease operating. Governmental mucking (affordable housing and housing subsidies) does not solve it, but rather tends to depress wages further while keeping RE values high. This is what the business owners, big RE tycoons, and owners of expensive homes prefer... bring in outside money to "solve" their local economic imbalance, instead of paying the necessary wages.
A few pages back a video was posted where several homeless people in CA were interviewed. One woman moved there from a cheaper town where she could afford rent, because she wanted to earn more money... and not pay rent. Bank the cash in other words. Making $20/hr while living free in a camp in coastal CA is a lot more attractive than making $10/hr and paying $500/mo for rent... or making $20/hr and paying $2k/mo for rent. I knew a guy who lived in the woods and hitched to a high paying job at a tech company every day!
I lived with homeless people for about 3 months in Santa Cruz. Definitely a place where rents are high, but that wasn't the reason why they were on the streets. The core "issue" was the inability or lack of motivation to have a regular job... and live a normal life. A majority were pretty hard core addicts, but that is kind of a chicken and egg situation, as many people with jobs and houses and normal lives are part time addicts, but they manage to keep things together. When someone moves to the streets then the addiction tends to become a very big part of their life. Maybe they could sober up and reenter the rat race? But the will is lacking, because the homeless life is pretty simple and easy. Nice weather, nice place, plenty of tourists to beg from, free food, etc.