It is not more popular but what's sure is it's safer, better and pricier. Invest in bitcoin when you still can before Bitcoin take the leading role 
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!The supply of bitcoin is also much smaller than usd, As far as im aware usd can have practically an unlimited amount so is valued somewhat differently to bitcoin.
Youre right, probably in terms of the price of dollars left very far from bitcoin but in terms of supplies, the dollar more than bitcoin, supplies bitcoin just 21 million in the world and this is very limited while dollars not.