Oh, they're much worse[1]. Is 4k 3840x2160 or 4096x2160? That's right, it's both! And 4096x2048! And 4096x4096! And about half a dozen other resolutions, many of which have no dimension of 4000 or 4096 pixels.

[1] https://en.wikipedia.org/wiki/List_of_common_display_resolut...