I'm happy to read evidence I'm wrong (I want to be wrong - it would make me much more optimistic about a fix), but my own life and everything I've read suggests the opposite - once someone develops a serious drug or alcohol addiction it leads to them destroying everything good in their lives and inevitably they either sober up or end up homeless. Nearly all of the people who stay homeless in the long term have some severe mental illness (including addiction). Short of an involuntary commitment which is its own kind of hell, helping these people is incredibly difficult.
I have multiple family members who fit this pattern and it's absolutely godawful. The addiction literally rules them. They will perpetually ask for money for "needs" then spend it on drugs. If another family member houses them, they will sneakily maintain their addiction and steal from family to support it when necessary. If you offer them housing on condition of getting sober, they will choose addiction and homelessness. If you offer them housing without condition, they will use it to stay an addict in perpetuity, who everyone else is paying for. I don't think this last is a remotely viable solution with the number of addicts out there, which is only growing.
I'm not saying this to condemn addicts/mentally ill people. I just want to give an idea of just how hard this problem is to fix.
I have multiple family members who fit this pattern and it's absolutely godawful. The addiction literally rules them. They will perpetually ask for money for "needs" then spend it on drugs. If another family member houses them, they will sneakily maintain their addiction and steal from family to support it when necessary. If you offer them housing on condition of getting sober, they will choose addiction and homelessness. If you offer them housing without condition, they will use it to stay an addict in perpetuity, who everyone else is paying for. I don't think this last is a remotely viable solution with the number of addicts out there, which is only growing.
I'm not saying this to condemn addicts/mentally ill people. I just want to give an idea of just how hard this problem is to fix.