Bitcoin can lead the digital world as it is a powerful payment method.
It can not replace the fiat money ever, but it can be one of the top (digital) currencies in the world.
What is needed for bitcoin to become more popular is when big stores implement bitcoin and people will gradually pay attention to bitcoin.
I dont agree with you.

I think bitcoin someday can replace fiat money, because today everyone have smartphone and bitcoin more easy to use in mobile.

hehe well, the example is so simply but yes i must agree with you about it, if we look at the past we can see that things start in that way i mean with small steps that nobody could imaginate that will end in things like smartphones etc etc.
also we should not forget that technology are going faster than never, so "Bitcoin is Becoming a Global Currency?" only if we wake up and take the control that banks and gov want to have about bitcoin
