One reason why it might be much higher in the US is the prevalence of swipe and sign. In Australia signatures are no longer allowed and essentially all transact

One reason why it might be much higher in the US is the prevalence of swipe and sign. In Australia signatures are no longer allowed and essentially all transactions are chip and pin (or tap if its under $100). This basically eliminates in store fraud as a chip cant be skimmed. No idea why ACH is so expensive / terrible in the US compared to other countries, I guess its the number of banks?