i think is impossible to dispense the dollar , bitcoin is not approving in lot of country , so if it will be that will be in the long future and only if undated state lost their control
yes that is right that it will take a lot of time and is not going to happen so early. because still majority of people do not know about bitcoin and it will really take a lot of time when all the people of the world start using bitcoin, in fact still only 1% people know about bitcoin.