Really they can’t do much of anything about crypto. All the examples you have are of people who used crypto to defraud people. There are elements of fraud that leave traces even when crypto is used. Crypto itself, without fraud, is aether (and yes I’m using the spelling on purpose). Think torrent, think porn, think cryptography. Once things find the internet and truly USE the internet they become very difficult for the government to do anything about. Sure there’s always going to be a few cases where the government gets lucky. But they’re the minority. And there’s enough crypto currencies already in existence that the cockroach element is in full swing. They’ll never get them all. They’ll never even get the majority.
Why accept a crypto currency based only on computerized ledger entries in preference to one that can be converted at any time into gold or any of several major currencies? Sailing ships were a great form of transportation -- until competition from steam and diesel propulsion came along and made sailing ships an anachronism.