On the other side, if the percentage of units affected is small, then the current approach by Apple could be a reasonable one.
I believe that the most 10,5 devices from 2017 got this issue. The question is how many user realize this? In the most cases you can see it only with white backgrounds. The white spot it most on the same place. This only can be design failure. I don't know what is the reason, maybe a chip on this location or maybe screen failure from beginning what's growing. I think there will be come more users in time with this issues. And as long this issue is present, i don't want to buy a new device that got a lifetime from a year.