The maximum numbers of bitcoin to be mined is 21 million bitcoins. Bitcoin can not be used as money by the whole world because it has a maximum cap. My opinion . What is your stand ?
I think if the price becomes stable like US dollars.
It would be become a world currency.
But it still need improvement on it's transaction speed, if it not improved i'm not sure it will be world currency
The problem about transaction speed that takes a long time will be no more soon because of Lightning Network has begun to develop, but dont know when. The big problem is its horrible volatility, great for investors but not for its primary purpose as Cryptocurrency