How big is your screen? At 27", I can clearly see pixels on 1440p. A 4k display with 150% scaling (effectively 1440p) looks much better. Maybe you haven't used a higher resolution? If so, you might not know what you're missing.
Not GP. But I have a 24" 4k (close to retina), the MBA screen and while they're nicer than the 27" 1440p I have, the latter is essentially worthless on macOS. With Linux, it's more than fine. Not super sharp, but quite readable. On macOS, the blurred text is headache inducing.
(cross-posting on both subthreads): I have native 1440p 120Hz on my main screen which is more than 30inches across (ultrawide). I can see pixels if I look close enough, but I do not see any pixels at usual reading distance.
I have used retina displays of various sizes -- but after a while I just set them down to half their resolution usually (i.e. I do not use the 200% scaling from the OS, rather set them to be 1440p (or lower on 13inch laptops)). I have not seen an advantage to retina displays.
