For what is presently happened now is Dollar obviously known by the people around the world. And most country adopting it too. But when it comes to online business, as an alternative payment, bitcoin is getting more useful into this scheme compare to dollars, especially the people in bitcoin world are very aggressive to make profit in trading platform,also in cryptocurrency.
yes bitcoin is the main online currency in preset time and hope that very soon bitcoin will also become the main fiat currency also. but in fact the majority of the people still do not know about bitcoin and that is the reason that bitcoin facilities are not yet available everywhere to use it as currency through out the world in fiat shops also. but in future we can expect that we will be able to use bitcoin as fiat currency also.