Wait, are you sure you don't have that backward? IIUC, you don't[] notice the difference between a 2K display and a 4K display until you get up to larger screen sizes (say 60+ inches give or take a dozen inches; I don't have exact numbers :) ) and with those the optimal viewing range is like 4-8 feet away (depending on the screen size).
Either that or am I missing something...
[]Generally, anyway. A 4K resolution should definitely be visible at 1-2 feet away as noticeably crisper, but only slightly.
I didn't use it for gaming though, and I've "downgraded" resolution to 2x 1440p (and much higher refresh rates) since then. But more pixels is great if you can afford it.
It's one thing to say you don't need higher resolution and fewer pixels works fine, but all the people in the comments acting like you can't see the difference makes me wonder if they've ever seen a 4K TV before.
For example, I have two 1920x1080 monitors, but one is 160 Hz and the other is only 60 Hz, and the difference is night and day between them.