I would say it IS eroding, but not rapidly. When you can print how much ever money you want (which is what the US can do), and when most of the world wants what you print (US Dollars), it is challenging to unseat the world hegemonic entity (the US and its dominance on the global financial system).

No other empire (in history) had the ability to print "unlimited amounts of fake money" (like the US does) AND make the rest of the world DEPENDENT on that "fake money". Until the world can figure out how to trade and circulate "other forms of money - fake or otherwise" that is not beholden to the US, I see slim chances of dethroning the US Empire.