"we would heavily crack down on user"

Learn some history. We tried this. It failed spectacularly, as if in slow motion, for decade after decade.

Nothing will stop trafficking since its a lucrative product and we live in a capitalist society, but crackdowns at least push drug use out of the open and cause people who get picked up to end up in jail or some facility rather than turned back out to the street where they often continue to commit more crimes. It keeps these chronic hard drug users out of public places like train stations where they are less likely to harm innocent bystanders. I've seen meth users on the train go off in racist tirades and start fights on transit just because someone happened to make eye contact with them. The status quo of not doing anything and shrugging our collective shoulders just leads to more people getting harmed, both the addicts and random other people.