We all have dreams for bitcoin that someday we will be able to use this coin freely and no other things to think since its already accepted by the society, and the government already stop holding bitcoins neck and allow it to be use without any policy or regulations, here is my dream this is how it will be organize
1 . BTC will be the primary money all over the world all the currency will be just secondary
This could be possible if the demand for crypto continue to rise into future because what i see here is that Fiat will lose its confidence and Crypto will be the next option.
2. All the world currency will be exchange to bitcoin slowly until its all illiminated
Ooops,this is not going to happen because in your top post already mentioned that fiat will become secondary and will not abolished .
3. Altcoins will be use for very country and bitcoin as its Superior
agreed on this because that same reason why altcoins has been created mate.
In this form bitcoin will be the global currency, no one will control it no regulations
well this is very early to predict because world is manage by politicians and i am sure they will never allow a decentralized currencies.