All of kendrick albums were made for different audiences, and S80 clearly got his fans, and when gkmc came out a lot of people felt like it wasn't better than s80...but as of today it is widely considered as Kendrick's weakest effort. And if we put all bias aside, there's no denying that Kendrick has indeed improved as an artist through the years.
Like a lot of artists said, there's an argument to be made for gnx being his best album, even though TPAB will probably always be his magnum opus for true music lovers. This shyt is classic west coast, so it ain't a surprise seeing west coast rappers claiming it's Kendrick's best, and probably one of the very best west coast albums ever made.
But the narrative about s80 being his weakest (yet still good) effort is not gonna change. Kendrick being a better songwriter in 2024 than in 2011/2012 is hard to deny, unless we don't know what a "songwriter" is

. Gkmc was definitely kendrick's most "traditional" rap album, which is probably why you think he was a better rapper on that album...it's probably more up to your taste, but that shyt ain't top 3 in his catalog as far as pure quality go.
matter of fact, there isn't a single list from a respectable magazine, or artist, with s80 not being ranked last. Having it anywhere else on a ranking is more of a guilty pleasure than anything.