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.
Some of the things I can imagine from adopting bitcoin in a country are:
- Tax receipts from cryptocurrency
- Save money Remittance
- Increase the interest of foreign investors to do crypto business in the country [exchange, mining farms, crypto-based services, etc.]
- Microeconomic growth among crypto users [traders, investors, miners and other services]
Some of the things above are what I can imagine from a country that is willing to adopt crypto as a currency or as a means of payment. However, for developed countries such as the United States, it is still possible only within certain limits as an alternative means of payment without legalizing it as currency.