What addicts need and what addicts want are totally different concepts. You're looking at this like legalizing drugs will make addicts all suddenly see the light and seek treatment. That's just living in lalaland. Sure, some might, but that's not going to be a large percentage. I'm looking at this like I've been around too many addicts and know that legalization social programs will not solve addiction at all.
The important question is about harm reduction. People trying drugs without support. The current system already produces addicts.
Can a different system lead to better results, plus as a side-quest defunds the cartels?