What the heck does the world need gold bars for if these are not allowed to be traded freely without being legitimately stamped with the logos of major refiner

What the heck does the world need gold bars for if these are not allowed to be traded freely without being legitimately stamped with the logos of major refineries? If gold still has to be controlled this way, why not just issue some kind of global money instead and stop drilling Earth for this? Also, what distinguishes a warlord from an ordinary dictator which still is allowed to use gold?