The reasons why some government in some countries fight against the presence of cryptocurrencies are because they think that crypto is always related to terrorism. They think that crypto eases the terrorists to do the transaction around the world easily. Additionally, they are thinking of the stability of the country financial among their societies.
Well, seeing the two most reasonable conditions, some countries (in this case, not all countries) may try to fight against the crypto. They sometimes make certain law of rule and regulation to stop and forbid their citizen not to involve in crypto. They also ban some advertisement for crypto.
However, crypto is sometimes anonymous and this uses high technology. Everybody can access it with some tricks.
I think that there is only a small chance for the government to kill crypto because they can control all people in their countries not to involve in the crypto world precisely.