The government doesn't have to make these disappear. They just have to increase the perceived risk and decrease their effectiveness until they're no better than buying on well-known corners or getting the phone number of that one friend's friend's friend.

That's mainly because drug practical prohibition activity is about suppression, not elimination. But I think it's worth noting that cops get paid to fight crime, not defeat it. As a general rule, I expect long-lived organizations to act in ways that self-sustain.