Depressing to learn of but a truthful observation I’m afraid. You would think tptb would have learned this lesson with the Prohibition experience.
I think those who postulate that the drug gangs will fold up their tents if drugs are legalized have the ones who have not looked at the lessons of Prohibition. The mob made more money on liquor after 1933 than before. The cartels will switch to other crime, or concentrate on selling to minors, or providing stronger or new varieties. Legalization will not be a magic bullet.