I've never seen UHF - worth a look?
As for 4K UHD releases of old films... they can 100% be better, rescanning 35mm film to 4K (with great care aka $$$) can indeed bring better/deeper colour and a sharper image etc.
Discussion
If you’re a fan of Weird Al’s work, UHF is an essential deep cut.
Star Trek: TOS was able to do a HD rerelease by scanning the 35mm negatives. They were even able to increase the viewable aspect ratio.
DS9 was shot with only what they needed for 480p NTSC. They can’t do the same thing, no matter how much fans want it. Hence the AI upscaling project.
..and Apple TV+ will film a new Hamlet in B&W 4:3 for artistic reasons.