I was reading a book on social life of the upper-middle class and new rich of the American 1920s and realized so many things we now do proudly were considered socially taboo back then. This was especially the case for clothing, makeup, women in certain public spaces, etc. What do you think will be different in the 2120s? Or maybe even the next 50 years?
If you make most drugs legal bar the most harmful ones, people will gravitate towards the less harmful ones because of legal availability. The mistake the US made is to make all drugs illegal, blanket prohibition has been a disaster
And I think what @sudo wants is decriminalization - that a person who gets arrested for using meth is treated for their addiction rather than go to jail.
For meth users, yes that is the right approach. For the dealers/ sellers etc, jail or something that incapacitates them is a better option