The Internet, after all, makes the dark web--and its myriad crimes, including ransomware, drug trafficking, and illegal porn--possible: without the former, the latter cannot thrive. The defenses we usually hear come in the form "prior telephone and postal systems facilitated bad stuff, too," which is a fact, but one that doesn't absolute the Internet, either. :/ """
^ What you sound like to me.
Like, I honestly just don't understand your point: these currencies (minus Bitcoin, due to proof of work being a bit ridiculous) seem like a very useful tool that you couldn't really ban anyway without taking ridiculously draconian measures (a la China and the open Internet, which is only barely working for them anyway) as--and this is kind of the whole point--there isn't any central actor running or maintaining it.