Video output and its perception, is not at all like audio output and its perception. We can make blunt statements about the limits of audio, because output dev

Video output and its perception, is not at all like audio output and its perception. We can make blunt statements about the limits of audio, because output devices behave (largely) linearly and band-limited, and because human perception can be modeled accurately and is also band-limited. You can't say the same about video. The output is an array of points, not even perfectly square or smooth, it is picked up by another array of receptors, and is non-linear. The limit being 1/60th degree is too blunt a rule of thumb. That's picking an arbitrary point on a curve showing how much better than guesswork a viewer is. The screen isn't a perfect output source, and the viewer isn't a perfect receiver, and the combined effect is you can easily observe the difference of 2K vs 4K images at distances those graphs say you wouldn't. I can easily observe the difference where it says I shouldn't be able to, and I'm nowhere near perfect vision. I would say pretty much everything in those graphs is off by a factor of 2.