The argument is that the fed doesn't matter if the USA can't defend its supply chains. It's not like the author forgot to take the fed into account. The argument is they only matter under specific circumstances.
That's a bit of an exaggeration. Maybe 10% of the US's supply chains can be considered to be under threat. If China stops trading with the US altogether, then it would be more, but China can't do that.
The world is not about to end. The Fed absolutely matters. Just look at what happened on Friday afternoon when Jerome Powell spoke and people thought that he sounded more hawkish than it was expected. Nothing changed, except some words, and the markets took a dive.
Powell can make the equities markets go down 20, 30 or 50%. It's a kids play for the Fed to orchestrate a recession, not to mention a depression. The tricky part is to orchestrate a soft landing, but soft or hard, a landing we will have.