What you might be seeing is actually the difference between matte and glossy display. I was like you, seeing how supreme 4K panel was ... until I saw glossy 10

What you might be seeing is actually the difference between matte and glossy display. I was like you, seeing how supreme 4K panel was ... until I saw glossy 1080p which was much sharper than 1080p matte (which desharpen the image) and not much different from 4K (to my eyes). (all comparisons took place on XPS 13s)