This is a nonsense response.

A bank exists not as an isolated entitity, but as a node in a local, regional and global network of transactions.

Your phone as a “classic banking infrastructure” (nonsense phrase) can’t do credit card acquiring or realtime transactions because it’s not connected to the payment rails, transaction switches and so on (like SWIFT but all of the other less global ones run by central banks and private entities).

In developed societies, instant settlement for bank-bank transfers is the norm, and cash flow is dependent on that.

Russia and Iran pay about 2-5% for above-board (non-sanctioned) cross border transactions due to their extra costs of not being in SWIFT and USD sanctions, and between 20-50% where physical middle-people are needed to move pallets of USD.