Khabib doesn't just get points for never being touched up in a fight for me. I pick him as the GOAT because I've watched enough MMA than I can pretty much eyeball his skill level. A similar reason I'm so big on Petr Yan right now, who is, to me, a better BW version of Fedor.
A bunch of factors I look at.
Grappling: Khabib
Chin: Khabib
Wrestling: Khabib
Pace: Khabib
Overall Skill: Khabib
Dominance: Khabib
Destroying top 10 p4p fighters: Khabib
Unbeaten streak: Khabib
List of names on resume: Some other guy
Khabib is the best fighter. He just retired early.
I think there is definitely an argument to have him as n1 p4p which is just the best but that's different to greatest of all time.
Doesn't change the fact that he's the best fighter.