Looks like the article is just putting the blame on cryptocurrencies on the growth of transactions in the dark web. But I don't think it's right to blame cryptocurrencies for it since they are just the assets being traded and not the drug itself being sold. I know it makes the transaction a lot faster but how do you supposed this drugs are being sent internationally? Of course logistics are also involved with this trade and one way to counter this market is tightening their customs on the imports happening. Let's not put the blame on crypto as even if they ban all of them I doubt the online drug trade would stop because of it.
In this case. those people in power can use cryptocurrency as a scapegoat for their failure to minimize the drug trade. Maybe these people should learn that illegal drug trade did not start when cryptocurrency came into being. This menace of the society has had been there decades ago. Of course, as part of our human nature, it can be easy to pinpoint something so that we can escape responsibility for our failure. Killing Bitcoin will never kill the illicit drug trade...