My answer is no bitcoin cannot replace any other physical currency because some other government instution banned bitcoin in their country and really for the fact that bitcoin anonymous well i can say theirs no way it can replace dollars because first dollar is the biggest contributor in economic trades as we can see what we see symbol for currency we trade online its always dollars, and that stated how power is the dollars thay influence global market thats why bitcoin is nobody for dollars.
Yes, for that matter as well, I see China has banned ICOs and bitcoin to currency exchange today.
Perhaps in future, the government may learn more on how to implement bitcoin ourthe societies.
I am sorry but I disagree with you two, there is a probability that bitcoin can replace fiat. Some countries has legalized bitcoin and some countries has banned it. People in Denmark are trying to decrease the fiat usage and replace it by virtual currency. I think bitcoin has probability to replace dollar but not soon.