I do get what your saying but imo if it’s not full legalisation of all substances then the black market still exists and life is a lil easier for junkies but the suffering involved in getting that crack rock or that heroin bag to the point of being in the junkies hand is still there.
We just passed the 2 year anniversary of legal recreational cannabis in Canada. Our lives are unchanged, junkees all crazy on marywannas didn't happen. You would be amazed though, at the fear and anger and misinformation and resistance there was among some sectors of the population leading up to legalization.
And that was just for cannabis.
Societal changes on a large scale take years, often generations. In spite of all the research, people often think with their gut and not their brain.
Diagnosing a problem is only the beginning. Ask any decent manager, you can have the best goals in the world but if you can't come up with a good implementation and get buy-in from your people, your goals will go unaccomplished.
It's the same in a society. Education must accompany legislation.