Until you reach transient shelter beds, which may not be saturated in a region (in some places in Chicagoland the work is going into outreach to get people off the street and into shelter beds as much as it is in expanding the number of beds), every additional unit of housing you build frees up some unit at or below that unit on the stack of housing. The effect percolates all the way down to long-term supportive housing rooms.
I don't really understand the intuition people have for how anything else could be the case. You make new housing available, people move into it, leaving vacancies. Pretty simple.
I don't have the impression most of my "fellow" americans even gave a damn about homelessness to begin with, so perhaps what you read as misunderstanding the market might simply be a disagreement of values—one party cares about the homeless, the other cares about salaried employees. May we all truly rot in shit.
> every additional unit of housing you build frees up some unit at or below that unit on the stack of housing. The effect percolates all the way down to long-term supportive housing rooms.
This makes intuitive sense to me, but I've really struggled to explain it in a way that makes it click for people.