Anecdata but I played games at 4K on a 4GHz Haswell (2013) + 1080 Ti (2017). Definitely faster at 2K but 4K was servicable. It's probably less true now that I'm 1+ years away from the hardware, but 4K gameplay is surprisingly accessible for modest hardware IMO.

I currently have a 4k monitor (+nv4070-super) and it does handle some games fine at 4k but for others I need to use 2k w/ upscaling. Depends on the game.

So good news, there is a fair amount of monitors coming soon which are super high resolution that offer a "dual mode" which is lower resolution that has higher refresh rate. They are pretty cool.

That’s not really true. I tried out 5K which would reasonably be quite heavy, but honestly with a DLSS it’s super viable. If you get the gaming versions of these displays, they also have dual modes and in that mode a 6K display is going to be less heavy to run than a 4K one and a 5K display is going to be 1440p.

I game at 6K… I don’t play shooters so it’s fine. I turn off VSync, get 100FPS+ in my game of choice (WoW, admittedly and oldish engine). 4090 GPU.

Upscaling tech has come a long way so games can run at lower internal resolutions than your monitor without looking complete crap on a LCD.

some of these newer monitors support a lower native resolution as well, usually with a faster refresh rate. it's a nice feature