Bitcoin doesn't have the power to replace dollar in any way. But yes, it may replace zimbabwean dollar as their economy is shattered. Jokes apart!

However, bitcoin and paper currency are genetically different. Dollar is a government backed currency where bitcoin is not. Bitcoin doesn't have any central authority. It is backed up by public trust. It will never be able to replace dollar or any other fiat currency unless and until any country adopts bitcoin as their national currency.