There is a major limitation, which is the different currencies of the countries. These fiat currencies are controlled by different policies and economic situations of their different countries.
This posses a threat to global financial unity. As many countries are under banked. At the height of these challenges, came a pseudo human called Satoshi, who created what seems like 21st century wonders(bitcoin)
From 2009 till date, bitcoin suffered too many set back, ranging from disbelief to doubt about its future.
But 10 years down the tunnel is a great improvement and acceptance of the first cryptocurrency - bitcoin.
The huge acceptance lead to the creation of several altcoins.
Now many countries are willing to involve in the cryptocurrency world despite some restrictions in some countries because according to an African adage "No one knows the Goose that will lay the golden egg".
I am seeing in the future where BTC will become a unified currency for the whole world.
To become a central currency the currency needs :
Approval from all the governmental bodies
Now does it seem possible ?
I don't think so.
Then we have to think about : Usage
Are mobile phones available everywhere? Internet? Will everyone be able to use them ? no.
The only reason so as why fiat is so popular is because it is indeed something very easy to use and convenient.
Then we will have the problem of Volatility which is good for us as an investment but at the same time it would not be something that we can go with when we are talking about stability of the whole economy.
Pseudo human ?
No
It would be apt to say the creator who did not take even a single penny from us for using such amazing currency.