There is no way Bitcoin can serve as a global currency in a centralized world, it's more of an asset than a currency, and it would be impossible to imagine it doing so as a global asset. It's not going to happen, but it's perfect as a people's currency. Bitcoin is people's money, and because it is a real decentralized digital currency, the government will never gain control over this beautiful innovation.

Moreover, who needs Bitcoin to become a global currency? None I guess, that's why the power to kill Bitcoin is not in the hands of the government or any law, the future that awaits Bitcoin is massive value as time goes on.