Just out of interest, will a DVD on a suitable player fed to a UHD TV upscale to 4K, and if so, with that much approximated data, how does it look ?
Part of it will always come down to how well the source material was transferred. But, much of it will look like 240p YouTube videos.
I revisit my Married... with Children DVD's often. The source material was done on videotape and it looks like utter ass. Even on a 720p set.