The University of Cambridge’s display resolution calculator, which is based on a study from researchers at the university’s Department of Computer Science and Technology and Meta, funded by Meta, and published in Nature in October, suggests that your eyes can only make use of 8K resolution on a 50-inch screen if you’re viewing it from a distance of 1 meter (3.3 feet) or less. Similarly, you would have to be sitting pretty close (2–3 meters/6.6–9.8 feet) to an 80-inch or 100-inch TV for 8K resolution to be beneficial. The findings are similar to those from RTINGs.com.

This is known since at least 2010, because our eyes are limited in optical resolution and in how big a surface we see.