Housing price is highly correlated with homelessness. In fact, homelessness rates across geographic areas are much more closely correlated to local housing costs than to local substance abuse rates, mental health problem rates, poverty rates, social safety nets, etc.

Whereas if you were right, you’d expect homeless rates to correlate better with local substance abuse rates.

Which is to say: if you ask yourself why one person in San Francisco is homeless and another isn’t, the answer is probably losing a job or drug abuse. If you ask yourself why someone in SF is homeless but someone in Huntington West Virginia isn’t, the better answer is access to cheap housing in WV.