Trees

I strongly doubt that capping distribution would feed the black market if paired with appropriate measures. I'm thinking of something like the Netherlands' addiction care program.
Of course there are people who go through a bottle of Wodka in a day or two and are still somewhat functional. That doesn't mean it's healthy or that it should be encouraged or facilitated by the state. But those people know how their addiction impacts their lives. And if they were offered free, non-judgemental help to kick the habit, I think most would accept.