I'm not an economist so someone please correct me / expand on this; I'm guessing this is kind of a "It's not a problem until it's a crisis" situation? So far other central banks haven't begun selling treasuries, they've just stopped buying them. But once one starts selling it could become self reinforcing? What could replace it? There doesn't seem to be any new hegemonic power on the same level. Could we enter a worl…
In some ways, this effect can have a positive impact on US citizens; demand for the US dollar requires supply to satisfy the demand. Where does that supply come from? Oftentimes: Printing. The US generally does not make a habit of telling US dollar buyers "no, we don't have any US dollars to sell you", so less demand on the dollar for reserve holdings can have a deflationary impact on its value. This can be combined…
But more broadly your comment doesn't really represent reality, whatever happens in the markets and economy the Fed manages inflation (or deflation) and it's much more complicated than a single relationship like you describe.
More interesting is trade, where the US consumes so much and pays out so many dollars for goods that places like China which run huge surpluses have few choices other than lend it back to the US.