Hundred years ago cocaine was legal. Coca cola is said to have had a little coca extract and another drink - maybe 7-up under a previous name - had a touch of lithium.
Obviously those were very different times.
The rising percentage of drug convictions (compared to all other convictions that put people in prison) could indicate overprosecution for silly things ... But obviously it most likely simply indicates the vastly increased prevalence of hard drugs ands once the Age of Aquarius
Have you seen whole communities devastated by drugs - towns where grannies are raising half the kids and parents are found dead of overdoses or get hospitalized with heart valve infections? How about women beaten while the BF was high, or teen girls pregnant because its hard to have good judgment while using, or babies born addicted, to parents who can't hold a job. I see these things. I work in health care in a region with high addiction rates.
Your one-sided views are a red flag. There may be pros to legalizing drugs, but if you fail to address the minuses your argument sounds ill-informed - or, worse, like propaganda.
As an aside: I have children with potential. I dont want them becoming addicted to any substance (incuding legal alcohol or cigarettes) that will hurt their health, cloud their minds, and take their money. And I am glad I never became an addict myself. It doesn't look like a pleasant or easy life.