65" LG OLED here, I can tell the difference between 1080p and true 4K video games on my Xbox Series X. I can also see a slight difference between 4K and 1080p movies on the Apple TV 4K (2017 model). Honestly though, the difference isn't huge, nothing like the days of going from SD to HDTV.
The bigger difference is with HDR/Dolby Vision content. The jump from standard dynamic range to HDR/Dolby Vision is stunning. Games and movies just seem to pop off the screen in HDR/DV. The higher contrast ratio and wider color gamut of these high dynamic range formats is more impressive than the 4k resolution jump, IMO.
The bigger difference is with HDR/Dolby Vision content. The jump from standard dynamic range to HDR/Dolby Vision is stunning. Games and movies just seem to pop off the screen in HDR/DV. The higher contrast ratio and wider color gamut of these high dynamic range formats is more impressive than the 4k resolution jump, IMO.