One consequent advantage of cheap that you leave off: Ubiquity. I can't assume that every place, even in the most sophisticated cities in the US, will support

One consequent advantage of cheap that you leave off: Ubiquity. I can't assume that every place, even in the most sophisticated cities in the US, will support NFC payments. Most don't, actually. So I still have to carry around a credit card and use it, with all the inconvenience and security issues associated with it. Also, that cheapness allows for user experiences that are prohibitively expensive for NFC. E.g., paying at your table after eating.