Treasuries could quite easily issue credit directly under the supervision of a Monetary Authority, with no interest charged, but with a payment into a default fund for the use of a Government Guarantee, and a payment for administration payable to Credit Managers formerly known as Banks.

It's not Rocket Science: but it is the disintermediating logic of the Internet.

To paraphrase John Gilmour's great quote re Censorship:

"The Internet interprets Banks as Damage and routes around them...."

"The future is already here -- it's just not very evenly distributed" William Gibson