I am underwhelmed by my 4K TV and maybe X1X already has the GPU power for 9th gen.

[SvennoJ]

Pemalite said:

The human eye doesn't see in terms of pixels.
However... You are right, there is a fixed upper limit... But we aren't anywhere near it yet.

Give this a read. - https://wolfcrow.com/notes-by-dr-optoglass-the-resolution-of-the-human-eye/

That article over complicates things, yet the base of it is that 0.4 arc minute is the absolute maximum in the fovea.

0.4 arc minute translates to 150 pixel per degree. So a 4K tv with 3840 pixels can take up 25.6 degrees of your field of view if you have perfect vision. It's overkill though and you only get that 0.4 arc resolution at maximum contrast. 20/20 vision corresponds to 60 pixels per degree.

Diminishing returns in full effect

Test subjects were asked to tell which picture looked more real. As you can see it turns into guess work over 100 pixels per degree