Here in India, local interbank transfers take less than 5 seconds with zero fee. I still can't understand why the ACH system is the US takes 5 working days. NE

Here in India, local interbank transfers take less than 5 seconds with zero fee. I still can't understand why the ACH system is the US takes 5 working days. NEFT/RTGS is the system in India which is equivalent of the ACH in the US and it takes maximum 1 hour to transfer funds.