I do not understand why I should compare these currencies. The dollar is for the government, and bitcoin is for the people. So it was from the very beginning of the existence of bitcoin. And bitcoin will never replace the dollar
Both Bitcoin and dollar are used by the people and people will choose one over the other considering the good option both the currency would give. Online, bitcoin is the best and for the offline , USD is the only option in the US. We cannot say one is better than the other. Both have the past god records and both have the bright future.