of course "normal viewing distances" is always implied when talking about monitors. And if you REALLY want to get pedantic you need to talk about pixels per degree. The human eye can see about 60. according to the very handy site
https://qasimk.io/screen-ppd/a 27" 1080p screen has 37ppd at 2 feet.
a 42" 4k screen has 51ppd at 2 feet.
a 27" 8k screen has 147ppd at 2 feet which is just absurd.
You have to get to 6 inches for the PPD to be 61