Good optimization works on any resolution, but 2K and 4K are really GPU intensive and it doesn't mean it's bad optimized, I mean, Wilds IT'S BAD OPTIMIZED, but I can give you Kingdom Come Deliverance II as a good example, it runs very well on 4K, if you have the correct hardware of course, that's not the game's fault.
But even now 1080 is still the standard for most people, it'll pass some time until we can say that 2K or 4K are standards.
In my case, I play everything on 1080p because my GPU nor my monitor can manage more, I'm not interested on 2K or 4K at all, but it must be nice playing on those resolutions with a nice monitor.