[Pseudoscience-is-malarkey (OP)]

Or perhaps we humans can't actually see 4K?

[Petrochemicals]

On small screens you cannot see the difference between 720 and HD. It's why they stopped making small HD tvs.

 [ Invalid Attachment ]

https://www.rtings.com/tv/learn/what-is-the-resolution

[evan_au]

I can spot the difference between a 2k computer monitor and a 4k computer monitor in my home office.

You can fit a lot more windows into a 4k monitor than a 2k monitor (and still be readable).
- But by default, Windows increases the size of text on a 4k monitor, so it's not exactly 4x the screen area...
- Sometimes I still have difficulty finding the right window, even on a 4k monitor!

[Bored chemist]

Or perhaps we humans can't actually see 4K?

Counting the "pixels" in a human eye isn't very well defined but the usual answers are over 50 MP.
This may suggest that the OP has a problem with their eyes- or maybe a bit further back.

[vhfpmr]

I can't see the difference between SD & HD unless I go out of my way to look for it, it's the programme quality that needs improving, not the picture quality.

Personally, I prefer my video without the compression artifacts too, they're a lot more intrusive than low resolution because they keep appearing and disappearing so that your brain never gets the chance to habituate to them.

[rohite]

I was never really keen on watching something at the highest quality, I can still watch youtube videos on 360p, doesn't really bother me. Although I don't have perfect vision, I don't have any significant issues either, there isn'y much difference between HD and 4k for me.
Don't think it's in indicator for poor sight.