And how do you propose someone actually transmits the anonymous cryptocurrency? The government can intercept any signal sent via electricity or electromagnetic waves. If they can't crack the code to figure out who is sending what, they can simply jam the network. I suppose you can try to establish a network employing quantum entanglement (so you could have spooky action at a distance.). However, I will probably be cold in my grave before this technology becomes close to affordable and feasible.
One can think of many ways. It depends on the threat model of course and it depends on the tyranny applied. If "running free software on your computer" becomes outlawed, we're far gone, so I suppose that you can have nodes running P2P connections without having your house raided. If that's not the case any more, then in the end, possessing a computer will be licensed like weapons, just like North Korea. I will admit that anon crypto in North Korea is a difficult thing to do.
So under the assumption that people can run free software on their computers, and have free encrypted P2P links with other people running free software on their computers, which makes it impossible to outlaw monero as such, but only its USAGE in commercial transactions, there are enough means to transmit transactions over the network. If you are in any case using your freedom to engage in forbidden transactions (because they are bluntly forbidden, or because you don't want to be fiscally stolen, or you don't want or are not allowed to get all the needed license privileges, or for whatever other reason your freedom to trade is taken away and you decide to keep that freedom), then the fact that you are going to engage in a forbidden transaction is not what is stopping you.
TOR was deanonymised with a big effort, because TOR is low-latency. Transactions don't have to be low-latency. They can be as slow as usenet used to be. If you leave out the low-latency demand, then anonymous networking is much, much more robust. If on top of that, you use obfuscation, then I think you're pretty well off. Of course some users will be caught. No system is perfect. But you will not be able to bring down the whole network.
You can think for instance about transactions hidden in images, so that a whole set of images results in a zero-knowledge proof of transaction, without being able to know WHICH image actually contained the "real proof" (somewhat like obfuscated ring signatures).
Miners will look for these proofs in different places, and if they discover valid transactions, include them. Of course, depending on the effort needed to recover the transaction, the fee has to be accordingly.
You could transmit transactions by snail mail. One can be extremely creative.
All this depends on the effort the state wants to put into it, and the effort people want to put into keeping/obtaining their freedom.
