To me the main difference is future and past. Bitcoin is the future and the real dollar etc is past. As world is going to be digitized so there would also be need of digital currency which is bitcoin. So this is the start and in future our names will write in history that we were the very early users of this currency.
I can't see the world in the future will be fully digitalized and bitcoin is they key to that. Even we count for many centuries there are still places that will not hug the world of internet due to the fact of poverty, government problems and being a poor country one. We are just speculating this good things since we are using bitcoin.
And if bitcoin will be truly used by all countries in the world we can't feel much freedom what we are experiencing today since it will become regulated no matter what. Id rather happy of the bitcoin status today than it will become the world only currency.