Historically, nations enjoying the status of issuing the world's reserve currency became great and wealthy empires - however this luxury never lasts forever and all of these empires imploded more or less after losing this status.
Historically, gold was the world's reserve currency. Gold coins from the "top" nations were more widely circulated and accepted because of their reputation, but other than that, it was worth precisely the same as any other gold coin of the same weight and composition.
For example in the 19th century, whether one was trading in gold sovereigns (uk), gold francs (france), gold rubles (russia) or gold dollars (usa), it was all the same. No country in particular enjoyed any advantage due to minting a globally recognized coin. The ratio between these coins was pretty much fixed due to the content/composition they had. If a country wanted to devalue they had to lower the metal content or weight of their national coin.
The monopoly-type-money scam and the huge benefit of its issuer in global affairs is a rather new phenomenon.