You need to review economics.
The federal government has stuffed its coffers with Federal reserve bonds. The value has been secured using a fiat currency as the collateral backing. We are… And are not… In debt. But here is what happens… The Federal reserve becomes defunct as a bank and its bonds become happy Rays of sunshine extracted from cucumbers. The world ceases denominating in Federal reserve bonds as markets route back to held assets and re-denominate in accepted currency standards.
Governments struggle to adjust as the bonds they rely on to secure their economic place are worthless. Taxation becomes difficult to enforce without secure policing and military authority and a loss of control over centralized banking.
This is why nations are in a bit of a gold and crypto rush. They will need something to back their currencies once the Ponzi schemes of central banking hit their certain mathematical end.