there’s already an established world currency, namely the U.S. dollar, and for all practical purposes it’s digital given that only minuscule transactions are made in physical currency ... what this is really all about is simply another attempt at de-dollarizing the world economy, presumably with some global/U.N. fiat currency ...
Special Drawing Rights are a sort of non-dollar IMF reserve currency that has existed since 1969, valued in terms of a basket of currencies. Similar to the bancor that Keynes recommended at Bretton Woods. It would have been the world reserve currency instead of the dollar.
Making the dollar the world reserve currency put us into the bind of the Triffin Dilemma, which began to show up in Eisenhower’s administration and prompted Kennedy to call for the end of silver coinage and silver certs. The problem of more dollars being held outside the country than we had gold to back them only got worse under Johnson and Nixon, and Nixon’s “solution” was to abandon the Bretton Woods Gold Standard, giving us the vicious inflation of the 1970s.