for me i think 1 day will come all fiat currencies will be lost and only cryptocurrency will remain
I personally do not think Bitcoin will replace all fiat currencies. Just take a look at Bitcoin. Slow confirmation, high transaction fee (especially for small transactions), easily clogged by some random fool, etc. If that would be the case, fiat is much efficient then. However, the existence of Bitcoin and other cryptocurrency is the key in moving into digital money as secured as Bitcoin.
so you'll buy a loaf of bread with your phone? isn't that a little weird?
Buying with your wrist is weirder.