What am I missing here?
120 FPS. It makes a HUGE difference for competitive MP gaming.
4K and 1440p look practically the same on a 27" screen. It's not until you step up to 40" territory that you'll notice much of a difference and that's way too big for the desktop (my screen is 43", 4K @ 120Hz on a desk...it's stupid for shooters).
1440p @ 144Hz is the gold standard for PC gaming with buttery smooth framerates, stellar visuals and crispy input. 1440p is the perfect pixel density for 27", textures eat up less than half of 4K HDD capacity and most console shooters should run at a consistent 120 FPS @ 1440p vs 60 FPS @ 4K.
If you're a casual, go 4K for the marginally prettier pixels and ganked FPS.
If you're serious, go 1440p for higher FPS, lower input lag and little loss of visual fidelity.
Hopefully PS5 gets 1440p support down the track, but support for 1440p on XBSX is a big reason I'm maining it this console gen. I can do 4K @ 120 FPS on my screen, but few console games will be up to it. 1440p @ 120 FPS is much more attainable and I'll be running at that resolution if given the option.