More or less all the UK banks are at various stages of involvement with blockchain technology. One use case I have seen openly discussed is cross-border, interb

More or less all the UK banks are at various stages of involvement with blockchain technology. One use case I have seen openly discussed is cross-border, interbank settlement. A large part of the fees you talk about don't even stay in the bank. I forget exactly where they end up but e.g. IIRC both the fed and ECB charge fees for clearing.