SMART people use Samsung Pay. Why? Because it can be used in all the many many places that does NOT accept Apple Pay. And that included Walmart until a couple of weeks ago.
It’s just near field technology. This same technology is in Apple devices, modern CCs, and even your driver license if you have a newer version. There is nothing substantively different. The difference is the platform, and remember that those platforms can be compromised just as easy as any computer system.
I have yet to see a place (other than Walmart) that accepts Samsung Pay but not Apple Pay. Apple Pay is by far the largest in the U.S.