One world, one currency? Certainly, one global currency would eliminate problems like intentional manipulation of currency values and it could make pricing transparent and eliminate foreign transaction fees. In fact, the benefits of a global currency is one of arguments for bitcoin by its proponents. But as logical and desirable as the idea sounds, it's unrealistic. In particular, there would be no tangible benefit to the U.S. government to transition to a single global currency. That's according to Scott Galit, the CEO of New York City-headquartered Payoneer, a global payment processor start-up named one of CNBC's most disruptive companies of 2018. "Despite the interests of lots of people out there in the Internet world who love the idea of frictionless commerce and frictionless money and avoiding fiat currencies, I don't see it," Galit tells CNBC Make It of the idea of a future single global currency. First, Galit says it's unlikely the U.S. government will ever allow people to pay their taxes with something like bitcoin, because that would mean the government's money would be subject to the exchange rate fluctuations of that digital currency. For example, by December, bitcoin had lost about two thirds of its value since the beginning of 2018, according to CoinMarketCap. If that happened to government money, it would not be able to meet its financial obligations, according to Payoneer.

Multicurrency background of the us dollars, russian rubles and ukrainian hryvnias OlyaSolodenko | iStock | Getty Images