Decriminalization of Drugs
Most drug dealers get recruited from drug users. Given that I believe that most drug use is literally self medicating for an unidentified medical condition, odds are high that many people growing, producing and selling illegal drugs like heroin, cocaine and marijuana have medical conditions that have forced them into a life of crime because illegal drugs are the only means to treat their condition effectively.
If simply taking the drug you NEED makes one a criminal, it's not too many steps away from making your money as a career criminal.
Growing and producing drugs takes substantial domain knowledge, skill and experience. If drugs get decriminalized, ideally it should be handled such that the people currently producing and selling them can transition to doing so LEGALLY. If it's not handled that way, substantial valuable knowledge will be lost.
I don't know how to make that happen. Presumably, it will involve some trial and error and there will be a learning curve.