FWIW, OP said they think legalization would stop the cartel, and you're describing the local effects of decriminalization. These are different things. Personally, I don't think either makes sense without having support systems already in place, like easily available SIS, rehab, readily available naloxone and a lot of other general welfare that we're missing in the US, like support for the homeless, mental health care, etc.

Just as sort of an analogy to what I'm saying, citizens of all the states had access to some gambling addiction hotline even before gambling was widely legalized.