I think this opinion is still hard to achieved, there is currently no global currency and a currency strongest still USD. The first phase that must be traversed bitcoin is beat USD, so that it can become a global currency.
I think BTC can be considered as Digital Global Currency since it is already used around the world and the majority of Digital currency nowadays are bitcoin.
BTC already surpass Paypal, Payza and other online currency due to it's fast transaction and anonymous features.
I have a very strong suspicion that you purchased your account purely to post for the signature payouts because i find it hard to believe that someone involved in bitcoin since 2015 could get so much wrong in just one post.
First of all you say that the majority of digital currencies nowadays are bitcoin, i don't even know where to start by saying how wrong that statement is, bitcoin is just 1 digital currency and could never be the majority of them
Secondly bitcoin is nowhere near surpassing PayPal in transaction speed. Paypal currently does about 115 transactions per second while bitcoin can only handle about 5-7 per second, big difference. Visa on the other hand can handle 2,000 transactions per second easily.
And last of all bitcoin is not anonymous, since all transactions are recorded on a public ledger called the blockchain they are there for everyone to see.
Have a read of this: https://en.bitcoin.it/wiki/Scalability