It is still difficult to say how the development of cryptocurrency will affect the economy of countries in the future. Previously, there was information regarding Japan for 2017-2018 after the legalization of the cryptocurrency there in April 2017 that the country's gross domestic income as a result of the circulation of the cryptocurrency increased a little, it seems, a little more than one percent. It was also noted that as a result of the circulation of cryptocurrency, the general well-being of people has increased.
But until today, states have shown very little interest in cryptocurrencies.

I think it's not, but the underlying technology that cryptocurrency was used is maybe useful to any country that adopted it because Blockchain is useful in promoting transparency that's why it's not more on the crypto thing but on the technology itself so let us say that cryptocurrency is not that important because it's only a choice the more important is the technology.

Depending on the resources and resilience of a country I think, Cryptocurrencies are like a double-edged sword, if we use it wrong it will be destroyed, but if we use it properly, it will bring prosperity to us. So in my opinion, cryptocurrencies are a great way for a country with standardized resources to go ahead and surpass other countries.

There are many countries that are already developed without cryptocurrency, therefore cryptocurrency is NOT essential for the development of the country. However, if the country adopts bitcoin, it can further be helpful for their growth. Also, it will be good for the people as they can freely use the crypto and it opens a new horizon for earning through mining's etc. Adoption of bitcoin will be recognized for your country. For example, before making bitcoin a legal tender no one knew about El Salvador but now everyone knows about this country.

In the question of the necessity and usefulness of cryptocurrencies, it is necessary to distinguish between such usefulness and necessity for the state and its government, as well as for citizens. For citizens, of course, cryptocurrency provides new opportunities and is very useful. I hope that over time, people's interest in cryptocurrency will only increase and its need will grow. But for the state and its government, cryptocurrency creates more problems and is minimally useful for them, but not necessary. States will not widely use cryptocurrency. On the contrary, they will try to regulate its circulation in the country as much as possible.