That privately issued money is asset-backed represents a fundamental precondition for it to be traded at par with central bank issued money, which comes in the form of currency (which individuals and businesses can use to settle transactions) or reserves (which commercial banks use for the same purpose). In addition to bank solvency representing a constraint on private money creation, banks additionally require access to these public monies in order to be able to engage in liquidity transformation – or money creation.
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