4K is too pixels if the screen is large enough. I had a Hitachi 28” 4K before I upgraded to an iMac 27” 5k. The text on the hitachi looked like crap, you could see the pixel corners and sub pixel anti aliasing coloring bleed through 10, 12, and larger fonts (that is on Windows, on a Mac you would see lots of blurriness via font smoothing).

Aesthetics matter, for a few hundred dollars more, it feels like I’m almost looking at paper (if it weren’t for the backlighting).