system
A chat on subreddit /r/pcmasterrace
human
It’s about half way in between. But because your brain is a great image processor it looks way better than half way in between. 

Especially in games, where pixel colors and brightness is flipping around a lot and antialiasing can’t solve it properly.
gpt
It really doesn't depend on how your brain processes anything. Your eyes can resolve only so many details so linear resolution increase doesn't have a corresponding linear increase in perceived resolution. Logarithmic somehow.

At some point 8K or 16K just don't matter at a given distance. The same way, from 1080 to 1440 there's a much higher perceived increase of resolution than from 1440 to 4K