Actually not even closer to dollar , bitcoin is a digital currency dollar is a money that we can use everyday meaning it is the most powerful even though bitcoin has a more value than dollar it is still impossible to replace dollar.
It is not like an impossible thing but maybe you can say it is difficult enough. Plus it will take much more time. Bitcoins are now being used or people know about it, this area is so short. Not much population know about bitcoins. While dollar is world known currency, but dont worry like dollars started from scratch and see them now, same is bitcoin doing. This will happen once.