I think one problem is that some merchants are unable to (or do not see the need to) upgrade their hardware. If I recall correctly, Apple Pay is using NFC technology and many machines don’t have that feature (I can only presume this is the case as I am living in NZ).

Samsung Pay ,on the other hand, emulate magnetic waves so that they can be used on ancient machines that only accepts cards by swiping its magnetic strips. This, plus other promotions, led to a widespread usage of Samsung pay in South Korea. My friends and relatives in Korea tell me they can actually leave their wallets at home!

I really wish this technology was shared between companies (fat chance!), so that it becomes more ubiquitous. Perhaps, one day people in Wellington and Pennsylvania could also use the latest technology to pay for their coffee instead of using pin codes.