For video, bitrate is definitely king. 4K high bitrate just gets insanely large. I opt for 1080p bluray quality when available over 4K usually. I looked into AI upscaling for video recently and it can be pretty good, but it’s a technology that changes fast so I’d rather store the original resolution and upscale in real time later (if at all).

For games, I find even FSR2 upscaling from 1440p to 2160p is excellent as long as it’s implemented properly (i.e. scaling the 3D world and not the UI), and FSR3/4 even better.