Relax, Chicken Little!

I think this is an interesting (if once again, over-the-top) article, and the central point is valid: Donald Trump is destablizing the international monetary (and virtually every other) order. But its conclusions are, I think, more than a little overblown.
My first point is that the author has been predicting the collapse for 50 years. "It's gonna happen!" predictions are kinda uninformative when they keep
not happening, like the Second Coming of Christ, or the World Communist Revolution, or the End of the World, or our Sun dying in a supernova (actually, only a nova, but why quibble).
It is true that the U.S. Dollar has not always been the "world currency" - indeed, for hundreds of years before 1776 it couldn't have been.
How the U.S. Dollar Became the World's Reserve Currency (Investopedia). But, to address the question, one has to ask
Why the U.S. Dollar Is the Global Currency? (the balance). By the way, it isn't, which is
part of the answer. "As of the third quarter of 2018, it makes up nearly 62 percent of all known central bank foreign exchange reserves. That makes it the de facto global currency, even though it doesn't hold an official title." Now, 62% is pretty good, but it is not a complete monopoly.
The problem with the author's argument is that it doesn't address the underlying basis for the Dollar's preeminence - the strength of the U.S. economy. The fact is, we pay our bills (except when Republicans are in charge). Yes, Trump has damaged that reputation, but bankers tend to be pragmatic. Trump is going to be gone, soon, one way or another, but the United States is not likely to be. The other contenders for "world currency" are not as solid, so consider the alternatives: the Euro, the Yen (both of which are "new" currencies), the Yuan or the Pound. Any look like better bets?
That, I believe, is the fundamental fault of the argument. Indeed, the 2007-8 economic crisis actually
improved the Dollar's position. Any future crises are likely to do the same, no matter how bad Donald Trump gets - and it is highly likely to get worse.