Are you talking about the resolution of the video or of the screen itself? Lower resolution video looks worse also because of the compression. I saw bigger difference from video compression than from screen resolution. E.g. good 1080p video looked better than bad 1080p video on any screen and resolution.
I have a 43" 4k monitor at ~1m distance and when I use the computer set up with 100% scaling it looks bad, I see pixelation... and "subpixelation". On a different computer connected to the same screen but something like 150% scaling it's like night and day difference. Everything looks smooth, perfect antialiasing.
This is the money picture [0]. Above a certain distance any improvement is imperceptible. But don't compare compressed video on a screen, it will add quality issues that influence your perception.
[0] https://media.springernature.com/full/springer-static/image/...
For plain video, 1080p at high enough bitrate is fine.
At "laptop" screen distances the difference between my Retina display and non-retina external monitors is quite noticeable; so much so that I run 4k in 1080p mode more and more.
8k is going to require those curved monitors because you'll have to be that close to it to get the advantage.