My biggest fear as we cease being the world's greatest power is that our relatively high levels of freedom are blamed for our weakness and we start following the lead of whoever is the world's greatest power. Tucker's somewhat notorious Russian grocery store and subway videos are an early version of the sentiment I'm imagining. Tucker doesn't blame freedom for the difference obviously, but if/when we decline, we'll start looking for inspiration elsewhere and elsewhere isn't very free.
If we are making a mistake believing our freedom was the cause of our dominance, it can also go the other way. As a person that loves freedom independent of its national utility, I don't feel confident in the conclusion that more freedom leads to greater dominance unless we hold everything else as being equal. And in the case of countries like China, everything else isn't equal.
Must the next world power be free?