Presently, USD has more fans than bitcoin. Because everybody is well aware of the value of US dollar. But in future, bitcoin will over take USD dollars.
I doubt that you can talk in this category - I like US dollar therefore I use it. People are using USD not because they are fond of it. but because it is a necessity for them, they have no choice.
You can either use strong FIAT backed by one of the superpowers and hope that it will stay strong or pick lesser FIAT with worse qualities, so there is not much of a choice there, is it?
If we discussed about popular, I think USD still more popular of course.
Bitcoin has it own market for now and people in community still try to spread widely and set it position, maybe in few years later when everyone knows what bitcoin is, then it will more popular than USD.
I think he can not be the same as usd popularity because bitcoin is just good for alternative payment mode only for online shopping or buying service online.. the adoption of bitcoin still low and they are few stores are accepting bitcoin and in other country accepting bitcoin locally..
The popularity still few i think below 10% world wide..