I mean /thread right?
He's over 40.
When you are a fighter and you are 40, you could've started fighting and training at 30 and yet you still should have seriously already been thinking about retiring for at least half a decade.
He can lose a fight to Brawldinado (not shitting on him, btw) and it won't be a stain on his legacy...just a mandatory call for retirement that will ultimately still be his decision to go along with or pass on by.
Believe it or not, in reality: the last fight of his that occurred in his prime was his first fight against Chael Sonnen. Even then, that might've actually been his first fight he had out of his prime.