Whilst this choice is entirely up to the respective merchants, there are studies that show transacting in cash cost more to merchants than via e-payments. They include labour costs for manual paperwork and reconciliation, the time taken to handle cash (despatch of cash to and from a bank as well as related cash-in-transit security), theft, pilferage, and also loss of revenue due to no small change. One such study may be accessed here - Economic Benefits of Going Cashless

Merchants in Malaysia continue to benefit from a range of payment options that can support their business needs. All these options will likely lead to merchants incurring some costs, including when accepting e-payments or cash. It is also important to note that compared to countries where QR payments are available, the applicable MDR in this country is among the lowest.