India have this very well figured out with its Universal Payment Inferface (UPI)[1]. Payment of any amount small or big is possible online as well as offline. I use the same interface to transfer 100k+ to my trading account and also to buy vegetables from a roadside vendor for few rupees.

This is an open system so lots of competition and zero lock-in is possible. It's su successful that world's 40% digital transaction are hapenning in India.

[1] https://en.m.wikipedia.org/wiki/Unified_Payments_Interface