I have thought A LOT about the solution to extreme drug use and extreme mental disorders. I believe there are only 3 solutions available today:

Extermination
Incarceration
Tent villages and tiny house villages
(And incarceration is probably not even realistic because we've stuffed our jails and prisons full of actual criminals. And I don't see anyone talking about insane asylums these days.)

Everything else is a pipe dream that will take WAY more money and WAY more political will than anyone is willing to spend in today's political climate.