state wants to get tax. the input and output of the money can not be controlled. also a serious competitor for bankers. also a good way to make money. countries are opposed to it. a money they can not control is troubling governments.
It is not the country but the government. People or the citizens tends to love using crypto butthe government do not loke it because they can not control it and that is what they do not want. They wantto be in control that is why they do not like it. But then it is not yhe country but the government. Not the people but those who are in controlled.
as far as I know, they are afraid of money laundering from this, but they also do not want to increase the risk of transactions that are difficult to track. well, but I think that is a long reason, because even though not with cryptocurrency, it still happens today.