I'd argue that centralization of money creation at any level is not ideal and that the monetary landscape used to be more robust in the US when many different entities could create their own notes (even if some on occasion went out of business).

And that another alternative solution would be that anyone/any entity who is willing to put a portion of currency supply risk at t0 in order to potentially have a larger share of money supply t1 should be possible (in addition to other lending activities).