Cubase and 4K monitors?

My son uses 3 27 " monitors and a 42" TV monitor. He is into games and I am quite impressed when I go to his house. That surround sound and video brings some big experiences to the entertainment portion.
Forgive my dumb question here but…is the purpose of obtaining these 2560 and higher resolution numbers is so fonts and graphics look sharper on a large screen ?

I see where a big 4k monitor can provide some massive real estate for mixers and recording functions it seems to be the pixel makeup that I don’t understand