I really do wonder where exactly 4K would begin if more and weirder resolutions were commercially available. Like, the fact that 3840x2160 is considered the canonical 4K resolution means you don’t actually need 4000 pixels, just a number that’s close to 4000. I wonder what would happen if someone dropped a 3800x2000 display just to mess with people.

That is just double 1980x1080, and if you shuffle it a little you get a 4000x2000 pixels, but that would mean your aspect ratio is different than what people are used to.