The United States Dollar is not going to die out anytime soon. As of now, it is one of the strongest fiat currencies in the world. However, its status as the reserve currency of the world can be under threat. Until around the 1920s, the Great Britain Pound was considered as the reserve currency of the world and that was the time when USD replaced it from that position. Sometime in the future, some other currency will replace USD from this position as well.