Substances are not good or bad. Their applications in society are what are good or bad, much like the distinction, in my mind, between Bitcoin and crypto. There is a right way and there's everything else. Fentanyl has an application in medicine. Its stratification into the market is what is bad.

I can't name a use for crocodil but modern medicine didn't begin to appreciate psychedelics until recently either. Meth.. alright there's a case for some substances just being bad 😆