Well I appreciate the effort, might need to look a closer look since my country has UPI and its basically free transactions instantly and even then we are constantly warned by our older generation to always carry cash too as there are places that will still not accept UPI or you would need to go to shop, do upi payment, get cash etc. and I kinda agree, I have seen/heard of even many fights happening because UPI wasn't accepted.

and that is when UPI is almost ubiquitous, I can't imagine a shop saying cards only. I think it might be illegal where I live.