I cannot claim personal experience, never having taken "recreational drugs", other than alcohol, and, a brief period of indulging in tobacco in my teenage years.
However, I do have a drug addict son, who has had many brushes with the law as a result of his drug use (including 3 months in prison).
My opinion is, the current systems isn't working. A death sentence for supplying, possession and/or using may, eventually solve the problem, but, I doubt it, and I am not advocating it.
To me, there is a lack of evidence regarding why addiction happens, the true consequences of drug us (including tobacco and alcohol). We do not seem to understand WHY some people become addicted and some do not. If you do not understand why, I don't see how you can "fix" it. Perhaps, it is a "feature" of being human, perhaps it cannot be fixed, I have no idea.
The term "addicted" applies to other activities than drugs, the most obvious being gambling.
My uneducated opinion, to reduce crime, and harm, is legalise all of it, regulate it and tax it, just like Alcohol and Tobacco. If the Politicians can resist being too greedy (with taxation levels) it would just be easier and safer to use the legal product. No doubt, just as with alcohol, a small proportion of users would resort to "illegal" means to satisfy their habit, and, would pay the penalty (in health/wellbeing terms, but, for the majority it would be an improved situation. We also need to make it clear that being "under the influence" of your drug of choice is not an excuse for unacceptable behaviour (ie in the same way that we penalise driving under the influence of alcohol).