Earlier quoted context omitted.
Wait, what? Selling fentanyl as candy in every street corner shop is going to fix this?
There is a broad gulf between selling something like candy and criminalizing its possession. You need to be of-age to buy beer. Sudafed is sold OTC but with strict limits. You need a prescription to get many pharmaceuticals.
Alcohol and nicotine are the only real middle ground in the US (maybe cannabis, but that's in a paradoxical legal status right now). Neither really seems to be in a "solved" state. Though I concede that at least alcohol and nicotine seem to be in a better state than fentanyl.