You can't solve all their problems with just providing housing, but it would some.

One thing I think people fail to see often when considering programs like this is the generational effect. A program to provide people housing might be considered a failure to some people because many may still choose to do drugs, will ruin their apartment, be violent to their neighbors, etc., some honestly valid concerns. But consider the shockwave 60 years down the line, for the next generations.

Homelessness and drug abuse are generational. Think of a person who would have been homeless who has a child. Was mentally ill and didn't take very good of the apartment, but not enough to not raise the child. Despite this, that child now has astronomically better chances at a decent life than if they had been raised on the streets or put into foster care just because they had housing and stability

You continue generation after generation, and though many people will be considered "failures" of programs like this, the rate of them continues to decrease because the success stories are now out of the system, out of the cycle.

The problem is half measures, which is what we have today. Bandaid fixes that don't get to the root of the issues homeless people deal with, keeping them in the cycle but doing... Something? So they can say look we care...