The transaction fees are flat 1.5%-2% for regular credit cards(may climb upto 4% for reward or amex type of premium offerings). The retail grocery business has gross margin of 8-10% which ultimately settles to net profit of 4%-5%. and paying almost half of your net profit for transaction fees is insane. In any case, the government owned non-profit digital payment system is really a great idea. People tend to have increased digital transaction which were unaccounted in the past, which also gives the correct data to government regarding current country financial habits.