There are a lot of times where the government tries to control crypto but there is no chance for them to do it, they cannot control it or even put tax in it.
Governments cannot control cryptocurrencies but they can issue regulations so that everyone is not allowed to use cryptocurrencies. Apart from that, the government can also impose cryptocurrency profit tax rules on users even if they do not legalize it as a legal currency or tender. Check out what the Indian government did for crypto users, taxed crypto profit of 30% and they did.
In addition, bitcoin can also be subject to government regulations, especially its users. This means you can't force yourself to use bitcoin in China as a means of payment or trade it if you don't want to be penalized. You also cannot avoid taxes if your country requires crypto taxes for its users especially if you own assets on a centralized exchange.