It sounds like maybe the problem is that the law is targeting the wrong people. I don’t think any kids should be arrested for smoking weed. If you want penalties for those who supplied it to them, that would make more sense if it’s considered harmful.

If a kid has a substance use problem, that’s a medical/psychological issue, not a criminal issue.

There shouldn't be a law dictating how old one must be to smoke weed. That's a parenting decision.