[andmalc]

1366 x 768 can look quite sharp on an 11". You were probably just looking at a bad screen.

AFAICT the reason than even expensive 11" laptops generally don't run higher resolutions is that at that size you can't tell the difference.

[comex]

Scaling the same pixel density up to 13" and 15" yields 1614x908 and 1862x1047, respectively. So that's equivalent to arguing that there's no need for a better-than-1080p screen on even 15" laptops. Certainly many people are satisfied with 1080p, but there's a reason that modern high-end laptops offer (much) higher-resolution displays.