We ran payments at our main front counter on a Samsung tablet and it was never an issue with our employees or customers. However, we had to retire it when Samsung stopped updating the OS and our payments vendor no longer supported our old version of Android. We now have an iPad there.
I didn't think of that specific use-case (only one or two apps for the whole life-cycle of the unit).
I'm still curious to know if it would be cheaper to buy Android units anyways and replace them as their software becomes obsolete as compared to buying pricier iPads that will keep up longer with software updates. Just factoring the costs here, not the environmental impact obviously.
In general I noticed a shorter support period in the Android segment as compared to iOS (Excluding terrible cases such as OnePlus dropping support almost instantly).