I don’t mean to be dismissive. But such an objection isn’t even mentioned on the web page. Just “forget about ...Smartpay” (I assume that means NFC of some sort). Hey, whoa, back up; how about we not forget about it and you folks tell me how this is better than a watch.
You can't lose it.
You can't forget it.
You don't need to charge it.
That's easy. Just swipe your smartphone over someone's arm until it beeps, then use your fingers (or phone's flashlight) to find it. Shouldn't take more than 3 seconds.
It's impossible for an implant to be 0 risk.
Removal is more complicated than implanting.
You can't change the data on it, so if you get skimmed you need a new implant.
However if it is re-writable (some are) you'll need to know someone/buy expensive specialized hardware.
I say all the above as someone with a magnet implant in my finger for the past 6 years. I still love having done it. But for practical uses like payment systems in an implant sounds like a horrible idea. (https://en.wikipedia.org/wiki/Magnetic_implant)
If it's basically an NFC tag, can't you make it read-write? Or is this potentially doing something more than that?
Also, how did you get the magnet implanted? Despite having no use for it myself, I still kinda want one.
In all seriousness, I forget my wallet more often than someone my age should. Keeping an extra couple of twenties in my car has stopped that from ever once being a problem. I've never felt the need to have a payment option on my phone or smartwatch, let alone implanted in my arm. What happens when you decide to change banks?
And beyond that, you admit to having a minor need this could address. Can you understand that for others that same need is much larger due to other circumstances?