This (clearing) is the biggest con ever and the reason banks won't stop it, is they make a packet out of having it "in limbo" for a few days instead of in accounts where they have to pay interest out.
Different from when it was actually necessary physically (pre-computers) to transfer the money. Most of it IIRC nowadays is done on a computer and obviously the physical cheques need to be redistributed (or do they?) but the money is only "moved" from one PC to another, which in theory is instantaneous but the banks are con merchants.
They deserve a
for it all.