They started to accept it. It is not an easy job for them. If you want to make a good job and maintain the system in your country you need regulations. And regulating cryptocurrency is not at all. And we have other factors like rich corrupted people that don't want to share their power with no one.
when bitcoin is legal it means there is a habit that they continue to use bitcoin with a large enough user capacity when it happens then the fate of conventional money will be questioned because the majority of the population uses bitcoin as a means of transaction.
But I don't think that the fate of fiat money can be jeopardize in any way because a country chooses to make bitcoin and crypto legal. We have to look at how Japan is managing it. I haven't seen the negative effects that countries and central banks are saying that will negatively effect a nation. They argued that its a disruptive technology, but Japan was able to go for more than a year now since accepting bitcoin and nothing has change. So its not yet proven that the financial systems or even their economy will be affected in a bad way. So I don't really understand why countries have demonstrated negative attitude towards cryptocurrencies.
I think it is because of the threat that poses it on the bank but Japan is looking on the positive side instead despite of the negative comments of the other countries and their competitor. I think it's time for the other countries to accept the legality of crypto currency in a different way if they had a problem with it, they should follow what Japan's been doing.