This was true thirty years ago, but is much less true today. The fraction of people that have serious mental illness is relatively constant, but the number of visible homeless people on the street has risen dramatically. What you're seeing today is a fraction of mentally ill people and then a larger fraction of drug addicted people stemming from the opioid crisis.
It's not the 80s anymore and that person screaming to no one on the street corner is more likely to be in meth psychosis than schizophrenic.
The reason I point these out is because I think the different groups need different solutions. Affordable housing isn't going to do anything good for something in the middle of meth psychosis. They'll just trash the place which is a complete waste of funding.
Don't confuse the two. Breaking down a working system that was evil without creating a replacement, without gradual transition, can (and did) result in a more evil system.
They were motivated by compassion but not right minded.