I'm not convinced. I've gamed at 4k on my PC and unless you get a big monitor then it's wasted. Not everyone wants a 40"+ monitor on their desk.
Vast majority of gamers are on sofa's in front of a beautiful 4k TV. Each year the number of 'gamers' sat at a tradional desk, playing games at low resolutions of 1080P and mid range resolutions of 1440P, is decreasing (mostly only older folk stuck in their ways doing this).
The most expensive 4K TV's (LG C9, CX etc) are far superior in quality/performance than any traditional monitor. PC monitor manufactures have truly ruined the market, far too expensive and horrible quality wise (backlight bleed etc).
Even phones are > 1080P, 1440P resolution these days.