How do you think: does crypto make criminal life much easier? We all know that criminals use crypto to sell drugs, guns, people and everything else. Did crypto make doing such things easier? Earlier criminals had to think how to keep their anonymity and get paid, how launder their money, how to not get catched with this. But now they can just use crypto and all the headache about this financial troubles passed away. Of course there is much bigger positive points of crypto and not every user of crypto is a criminal, but anyway are you worried about this? Criminals also worsen the reputation of crypto that is not really stable itself.
You write as if many people are now engaged in arms trafficking and selling large quantities of drugs. After all, to buy or sell small lots, hardly anyone will use the cryptocurrency. For smaller lots, it's better to use cash. I do not think that the emergence of cryptocurrency significantly increased the level of crime. This is a contrived topic.