The internet requires a bunch of physical infrastructure to operate and crypto requires use of that physical infrastructure. Physical infrastructure is definitely controllable by governments if they so desire. The CEO of Comcast isn't going to go to jail to ensure that Bitcoin is accessible to the average user of their network.
Sure they may try but I don't see how they could make Bitcoin any less accessible than Bittorrent is nowadays. Doubly so considering that if this was to become a legitimate issue cryptocurrencies could just update their peer discovery mechanisms to minimise the meaningful damage that governments or ISPs could do.
The cat is out of the bag and unless governments want to start seriously pushing into authoritarian territory there's very little they can do to stop it. Could China kill cryptocurrencies within their borders? Probably. Now could the US or countries within the EU? Probably not. Particularly in the US I can't see this ever happening. It's too close to infringements upon the first amendment that I can't see any meaningful legislation or regulations sticking.
