The UPI digital payment system is clearly a success in India.
"It processed $1trn in transactions in 2022, equivalent to a third of India’s GDP. It has grown from around 17% of 31bn digital transactions in 2019 to 52% of 88.4bn transactions by 2022."
https://www.economist.com/special-report/2023/05/15/a-digital-payments-revolution-in-india