Sort of true in principal - if no one has faith in their currency then it will have no value and no one will use it. But as long as some people value it, and banks have the magical power to fraudulently create customer deposits out of thin air, it’s pretty easy for a few banks to collude and create a flywheel of credit creation building up each other’s reserves with the other’s loans. It was this sort of behavior that kept crashing the currency before the Fed and was used as the excuse for a central bank. Just ending the Fed isn’t enough. You can argue that without removing their ability to create deposits they will devalue the currency into oblivion. The central bank serves a role of limiting this potentially infinite expansion, but really only directly addressing the root of the problem, which is that every single bank loan literally creates customer deposits out of nothing, then the currency will continue to be used as a tool of fraud and enslavement.