I think another way of asking the question is 'what would happen if other drugs were made legal'.
If alcohol was made illegal again, as it was in the US 1920s, then maybe things would be worse due to lack of regulation. I don't know.
I can only stick to my idea of tests of each drug per ratio of people in terms of health and so on. I cant see any other way of proving point one way or the other, although I anticipate a certain answer.
Didn't alcohol consumption rise to record levels during the American prohibition.