Question Setting 4K laptop display to 1080p

[A Furry Peanut]

Does setting a 4k laptop display to 1080p help with battery life and when the 4k screen downscales to 1080p, how does the screen quality compare to a native 1080p screen? When I downscaled my 4k screen to 1080p it looked like things were slightly blurrier which seems to make sense considering that I went from 4k to 1080p but shouldn't 4k vs 1080p be indistinguishable to the human eye on laptop displays? Is this some placebo effect or perhaps a scaling issue?

 

[NightHawkRMX]

Downscaling screen will improve battery life. Even though there is a minimal difference between 4k and 1080p on laptops, there is a reason companies put 4k screens in laptops. They do look slightly better.
Also a native 1080p screen may look better than 4k running at 1080p. I know 720p looks much better on a 720p panel than a 1080p panel with downscaling. Downscaling has some flaws due to the scren resolutions not dividing evenly if i remember right.