Dark web vendors do not take any form of payment other than cryptocurrency.
You can use crypto to buy drugs on the "dark web" but like all crypto things it's not a system for the masses. I had to explain E2EE one of my friends who thought Snapchat was better than iMessage for buying drugs because it "deletes" the message. There's no universe she's gonna figure out crypto.
I’ve never met anyone who has bought drugs on the dark web and I know more drug dealers than most people.
Weed finds it way to the people who need it from the people that grow it through a network of middlemen/brokers. Cocaine, meth, and fentanyl wholesaling is pretty much cartel dominated.
Unsure about other drugs, I know online is a common way that obtain LSD (and other psychedelics like 5-MeO-DMT, 2CB) but I’ve always bought it in person.
Source? “Dark web” is sort of a perfectly-useless mix of trust and trust-less for a high-volume actor. You don’t know who’s on the other side, definitively. But they at least know a mailing address you can get to.
Your point about the mailing address is a good one though. I had not thought about that.
I know someone who buys their drugs rarely but in large quantities in this way. They are not a dealer but essentially use quite a bit and ask friends what they want and then order a couple thousand euros worth of stuff to get the volume discount and to reduce the amount of packages.