Thing about resolution is, it's totally dependent on screen size. I don't feel like at 4k 55" the scene complexity is much better than 24" 1080p (or 29" UW). But being able to scale the image quality to an ever bigger sized display is exactly the point. It also changes how a lot of the settings are perceived, some things stand out a lot more than others and some weakness that aren't otherwise apparent are really obvious (an egregious example is lod models in open world games; there's a harsher contrast between the lod models in AC Odyssey playing at 4K max vs 1800p with AA low, and that's because you have some elements of the scene be crystalline sharpness and unbelievable details, then 2/3rds of the screen is covered in ****** lod models that look like jpegs from the dial-up era. this makes the difference be much more jarring than having the game run at lower settings & that's why ps4 pro/xbox one x seems to have so much praise, because everything gets blurred together and if you sit far enough from the TV it gives a really good impression - only problem is I sit like 1.1m away from mine so it's obvious it's crap).
All that being said, the problem for me is not so much that I can't live without a really big screen but rather that overall quality of monitors is garbage compared to high end TVs even when we compare the highly priced models. Maybe if there were some OLED options for a 34'' UW that wouldn't be the case but in general it's just so bad. So, at the end of the day it just doesn't make sense to go for a monitor (worse IQ, just as expensive if not more so, less flexibility etc) unless you simply can't/don't want to fit a TV in your space. Especially when imo the biggest graphical advancement of them all, far above any ray tracing or other such non-sense, is HDR. When done right it's a totally jaw dropping experience, and the HDR performance on TVs is just unparalleled.