Absolutely and he could have easily been high up there amongst the best to ever do it if he at all took training seriously.
Once you realize that BJ came from a rich family, the story of his career makes a lot more sense because you can see how spoiled, arrogant, and lazy he is. He had one of the best chins ever, amazing natural flexibility, was obviously a BJJ phenom, and tremendous boxing... but he was fighting 3 weight classes above his own "for the challenge" and his biggest weakness was cardio? lol Why do people always give this a pass?
BJ easily had one of the best natural skillsets for MMA in history but he coasted off of it for years and had a very small window where he actually trained properly which absolutely falls on him. Why do people fault a guy for having a bad chin and yet give a free pass for being "unmotivated" which is actually something that is under their control?
He still had some amazing highs in his career because he was that dangerous of a fighter but I can't imagine how anyone can look at him and say "he reached his full potential" considering what he was working with.
Whereas GSP was hungry and improved significantly since their 1st fight, BJ was still essentially the same fighter as before and thus got absolutely destroyed in the rematch. Genuine LMFAO @ people using greasing as an excuse for the outcome of that fight when BJ has 0 submission wins from guard in his career, was getting taken down at will, and was gassed in a matter of minutes. Then he had his mom write a letter to the athletic commission to complain for him LOLLLL again, his story makes a lot more sense now, doesn't it?
You can't take away his accomplishments even though his post-MMA career has been a terrifying cautionary tale (not all of which is caused by CTE even though that is a big part of it) but to me, BJ fits more on a "best natural skillsets ever" list than he does a "GOAT career list". He simply was not consistent enough to be called one of the best to ever do it. Despite being a multi time champion, his potential still outweighs his success IMHO