The Netherlands partly has this system, where cannabis sale is 'tolerated' for shops with permits, and where advertisements are forbidden. The system is far from ideal, but I think better than complete (de)criminalization. Additionally, the discussion about drugs is very open thanks to a number of publicly funded organizations. They do not hesitate to also note the positive sides of certain drugs, which all the more encourages a conversation about the responsible use of drugs.
Portugal has gone even further in decriminalizing other (more addictive) substances [1] with fairly good results.
[1] https://www.theguardian.com/news/2017/dec/05/portugals-radic...