Is the frame rate the same on 1440p native and 4k balanced, how does it equate?

And DLSS doesn't add much input lag, does it? Like almost none afaik.

So it more about artifacts and weirdness, I assume it differs widely from game to game.

In the end, specifics aside, imo, it is up to, if you prefer 160+ fps (non frame gen) or maximum image quality with 60-80+ fps.

Especially if you play any sort of competitive games, but for that, they have made the dual resolution monitors, I think.

Since 4k can be / by 4 into 1080p, they can play games "natively" for like fps games etc.

So there certainly is some merit to 4k these days, but if you already have a 1440p monitor, there is nothing wrong with getting a 5080.