No it's not. 2560x1440 has terrible PPI on larger screens. Either way with a 4k monitor you don't technically need to game at 4k as most intensive games offer DLSS anyway.
Too much personal preference with PPD. When I upgraded to a 32" monitor from a 27" one i didn't push my display through my wall, it sat in the same position.
Not entirely clear on what you mean, but if you refuse to reposition your display or yourself after hopping between diagonal sizes and resolutions, I'd say it's a bit disingenuous to blame or praise either afterwards. Considering you seem to know what PPD is, I think you should be able to appreciate the how and why.
Yep. I have both 4k and 1440p monitors and I can’t tell the difference in quality so I always use the latter for better frames. I use the 4k for reading text though, it’s noticeably better.
There are good 4K gaming monitors, but they start at over $1200 and if you don't also have a 4090 tier rig, you won’t be able to get full FPS out of AAA games at 4k.
I've seen analysis showing that DLSS might actually yield a higher quality image than barebones for the same graphics settings owing to the additional data provided by motion vectors. This plus the 2x speedup makes it a no brainer in my book.
Also, ultrawide monitors. They exist, provide more immersion. And typical resolution is 3440x1440 which is high and and the same time have low ppi (basically regular 27" 1440p monitor with extra width). Doubling that is way outside modern GPU capabilities
Almost no one plays on native 4k anyway. DLSS Quality (no framegen etc) renders at 1440p internally and by all accounts there is no drawback at all, especially above 60fps. Looks great, no noticeable (excluding super sweaty esports titles) lag and 30% more performance. Combined with VRR displays, I would say 4k is perfectly ok for gaming.
I watched the same video you talking about [1], where he's trying the PG27UCDM (new 27" 4K 240Hz OLED "gaming monitor" [2]) and his first impressions are "it's so clean and sharp", then he starts Doom Eternal and after a few seconds he says "It's insane [...] It looks perfect".