I am definitely not calling him the GOAT, although he is certainly one of the best to do it. He's 40. He has earned the right to be selfish and think of himself and his bank-account at this stage (unlike, for example, Tyron Woodley). At least he's up front and honest about it.
He has earned our respect. In addition to being a stud, he's also been a pretty decent role-model, as far as MMA fighters go.
Saying he's not a true champion and detracting from his contribution and success in two divisions is unfairly disrespectful. The guy is a damned Ogre.