I do not believe that exactly bitcoin will become the official currency of any state. Most of the coins found are already owned by whales. For the national economy, a more flexible cryptocurrency is needed.
I believe Bitcoin is a global Crypto currency in future because future Economy is positive in all the country so we expect the official currency. We are move to the updated technology so we just follow the same way. But some countries are creating the restriction at the same everyone supporting to crypto platform automatically they will accept the new trend.
We can see more and more acceptance from different countries around the world. Technology could take the world step forward and the same won't cause bitcoin to be adopted as the national currency of United States. Already dollar has taken its role dominant over each and every currency that has been used around. Countries that are economically down could adopt bitcoin making it get used similar to fiat and the same will help in overcoming the economic downfall.