What if I told you that all the "cool details" in skins and champion models...
...Show up as messy and really awkward looking visual artifacts in game? All the individual rust stains and marks on Nautilus look like a weird digital pattern when zoomed out. Desperada Cassiopeia's dress looks like a bunch of black and white dots. Old Pentakill Mordekaiser looked like his metal was really fuzzy and was leaking pixels everywhere. Olaf's muscles look like watercolors. WITH PIXELS LEAKING EVERYWHERE.
Complain about the removal of small details all you want, this game doesn't anti-alias hard enough to stop them from just showing up as pixels. Annoying pixels.
When riot updates skins, and some of the smaller things are gone and colors changed, believe me - there's a reason.