The answer is so simple. But those making fiat currency don't want us to twig onto that. They dream of "perpetual debt." AKA the perpetual bond.
Consider the concise Wiki: "A perpetual bond, also known colloquially as a perpetual or perp, is a bond with no maturity date, therefore allowing it to be treated as equity, not as debt. Issuers pay coupons on perpetual bonds forever, and they do not have to redeem the principal. Perpetual bond cash flows are, therefore, those of a perpetuity."
Note the game in the phrase -- "...therefore allowing it to be treated as equity, not as debt."
This simple answer is to "jubilee" the Fed and its "debt" holdings, by nationalizing what the definition therefore calls "equity, not debt." Abrogating in one fell swoop the Fed's holdings would be disruptive in the short term but massively stabilizing in the long term. It will happen by default in time, anyway, based on Stein's law.
BTTT!