The dollar's not going anywhere. What do you think will replace it and why? Tying a currency to a limited resource like gold/silver is what brought the Great Depression. Bitcoin is just a way for bros to suck money out of the avaricious gullible (don't think so? Show how it's actual currency.) Switching to a different fiat currency gives us choice of... the menbinbi (yuan), or euro. There aren't enough euros to work, and using the menminbi gives the CCP the ability to collapse the world economy as they devalue it to stay in power. Just look at the mess China is in now.
Although I disagree with him on nearly everything Frederick Bott's got an interesting idea, linking some kind of currency to energy production, but the linking part is all hand waving.
To the extent that there's an actual 'American Empire' (post WWII global system based on the Bretton Woods Accords) the Americans have been backing away from this since at least the Reagan administration. Just look at the makeup of the tonnage of the US Navy; they've already transitioned from global trade protection to global power projection. The original idea behind the BWA was removing the commercial reason for colonial empires, plus postwar recovery of course. I don't see that as particularly un-American, but we can agree to differ there.