When I think of currency the first that comes to mind is bitcoin and I think that the bitcoin will become the world currency in the future. It is been used for payment and services so it is a currency, though not all merchants and companies accepted it. It is started to get recognized globally.
bitcoin is outdated sometime it the future a new currency will rise just like bitcoin did the odds are not that bad 2009 to 2018 had 1300 new currency's i guess we can see another 1000 or so in the next 10 years or so?