Money isn't even a real thing, but simply a measuring tool to denominate commerce. To the currency issuing government it is a tax credit, and to the private sector it is a scorecard entry.

Money only achieves importance from its ability to deploy real resources in the private sector where they can be accessed by the government. This is achieved via taxation that can only be paid in the tax credits the government issues. The issuing government never needs its own currency back to enable its spending, but it does need us to need the currency, and occasionally to have less of it.