The most incredible thing about UPI is how it was embraced by even the poorest in the remote corners of India. One of the former finance ministers of India talked in a dismissive tone in the parliament about rural India adopting digital payments when the current government announced "Digital India" plan. Some one made a meme video out of it mocking him.
https://www.youtube.com/watch?v=aCnv8gwN0ug
Another video showing the ingenuity of a road side vendor https://www.youtube.com/watch?v=uY2156ecRDQ