Those are the adulterants, not the drugs being adulterated such as heroin, meth, and MDMA.

For the most part, no customer wants fentanyl. The dealers like it because it's a cheap booster for cutting the drugs that their customers actually do want to buy. It just has this unfortunate side effect of making small overdoses lethal.

That's why "ending the fentanyl crisis" is a curious goal. We had a perfectly good War on Drugs going on, but fentanyl is making the illicit drug industry too dangerous. You'd think that if we wanted to stop drugs, and we knew how to do that, we'd stop drugs. Instead we're stopping fentanyl, so we can get back to the regularly scheduled version of the War on Drugs that was always intended to last forever.