If everyone in the world gets into crypto and cryptocurrency will become an official global currency, do you think bitcoin then will stop depending on fiat currency? Or will it just co-exist with fiat?
The concept - the official global currency is rather vague. Under it everyone can understand the situation in their own way. The states will allow the circulation of the decentralized crypto currency, but they will not actively support it. I also do not think that they will use it in international calculations. For states and their structures it will not be profitable. Decentralized crypto currency is very suitable only for ordinary citizens, they will be its main users. Crypto currency will only go in parallel with the national types of currencies, they will complement each other with their own merits.