You can't push medical treatment on people, the uptake is much worse than making available free housing.

And that's IMO part of the problem, combined with some pretty bad history regarding domestic use of asylums etc.

You can't give somebody who's had a mental break a house/apartment/etc in the general population no-syringes-attached and maybe a once-a-week drop-in and expect things to go ok. That just results in places getting attacked with drug-fueled parties etc, and it's not particularly great for the neighbors.

There is group housing, but again if you stick an unrepentant addict who has mental issues in with people who are trying hard to recover, that'll negatively influence their living situation and mental health situation of those around them.

So... first-start housing needs to be in a controlled or semi-controlled environment that can allow people to recover when they're not in a good enough mental state to make sound health/life choices. You can't be no-strings-attached without it impacting those around them and their own ability to recover, and you just end up with a shit hole (literally in many cases) full of junkies, dealers, and people screaming at walls.

As those who are willing to improve things do so, and gain the faculties to make that decision, the housing situation and independence can change as well, but the care, housing, and healing need to go hand-in-hand with some basic ground rules for the good of all.