Because the use of Bitcoin can be used as a long-term investment asset because of hedging, it is no wonder that many countries continue to try to adopt Bitcoin in their own way.
Countries using Bitcoin as an investment asset will surely benefit from it if they have blockchain and market experts advising and managing the investments because buying and selling at the right time is the key to making full use of the opportunities to gain as much profit as possible.
If a country is investing at the wrong time and then selling its coins at the wrong time because of the money being reserved for very long, this is only going to make them suffer.
Bitcoin can contribute to a country's economic growth by becoming a country's reserve asset, using El Salvador as a good example, They started buying Bitcoin when it was around $40k, There Bitcoin portfolio would right now be in a good profit, whereas the profit which has been realized can be used to develop the country and the profit be put in the other areas of the economy, thereby boosting the economy of that country.
Using Bitcoin as a reserve currency can have its pros and cons because its price doesn't move in one direction. It's true that if the price of Bitcoin goes up when a country is using it as a reserve, they will have a lot of profit from this, but if the price goes negative, they will lose money, and I don't think a country would be ready to bear that because the money will be in large numbers.
A country that has a government that works only for the people and doesn't have such thoughts might have economic growth using Bitcoin.
As of now, only oil rich countries are doing like you have mentioned. All other countries are becoming tax heavy which means there would be less chances for letting bitcoin grow in their country. Probably government may try to regulate bitcoin in such a way where they could still tax every bitcoin transactions. I am not seeing any possibility for such innovation to become practice. So, growth of bitcoin might remain without the support of governments.