I think part of the "retina" branding was that pixel count doesn't matter beyond that point. It's indistinguishable to the eye, so beyond that point more are n

I think part of the "retina" branding was that pixel count doesn't matter beyond that point. It's indistinguishable to the eye, so beyond that point more are not better. It's debatable if that's actually the case, but it's an implicit part of the marketing. The idea is that you'll never need to look for a better screen.