Taxes. They make a sacrificial lamb out of a few high profile tax dodgers. All the power structure has to do is convince norms that crypto is scary/dangerous/tax risk and they will have done their work. I think someone else made the torrent analogy. The crackdowns on torrenting were quite successful. They scared the public with some messaging, made a big noise about canceling regular people's internet service, etc. Torrenting has ben kept as a niche instead of mainstream. That's all the power structure needs, it doesn't have to completely kill crypto.