The ideal optical design is such that your optical spot size/MTF is matched to your pixel size in a way that

* subpixels are blurred, and it's hard to see the boundary between pixels * you still have enough resolution to resolve text clearly

Our headset has that, and I'm confident Apple's will too.

Yes, I should have been more specific. The broader point I think stands: you need a very high resolution screen and high-res image (and thus rendering compute power) to get even a good-enough viewing experience, especially for text - say what you'd get from a mediocre FullHD monitor.