This is a boring argument and the poll is clear about it. Dana hates GSP for retiring with the belt twice, good enough, but Usman isn't the GOAT nor close to being the GOAT at 170, and if we are comparing era to era he's not second place either. It made lots of sense to hype him as GOAT while he was a champ and defending and hopefully (for the ufc) going on a giant title defense run, but now that he's lost 3 in a row I don't really see the appeal other than just sucking him off to his face. Usman had a long long way to go.
The worst part about this shit is Usman was an awesome champ and great fighter, saying this when he never got close to a best of all time just makes his career look stupid if you dive into it.
Here are some objective stats.
Record
GSP 26-2 - 93% win rate
Hughes 45-9 - 83% win rate
Usman 20-4 - 83% win rate
Title fight record (including interim)
GSP - 13-2
Hughes - 10-3
Usman - 6-2
Undisputed Championship Defenses
GSP - 9
Hughes - 8 (I included Riggs fight, still a defense if a challenger shows up and fails to make weight imo)
Usman - 5
Number of divisional world championships
GSP - 2
Hughes - 1
Usman - 1
Unresolved losses
GSP - 0
Usman - 4
Hughes - Too big of a list for me to go through lol
Weakest Defense
GSP - Nick Diaz got to slide into title contention only because Condit had a knee injury. He was on an 11-1 tear in the 2nd rate leagues and had beaten BJ up pretty badly, but still shouldn't have got the shot and only did because of injury. Note here that the undeserved title shot wasn't rewarded with another title shot after it was clear they weren't in the same league.
Usman - Masvidal 2x just pure LOL. 6-4 coming into his title fight, which there is no shit to be talked about as it was a short notice replacement. But we all saw it was a joke of a fight and the rematch was an even bigger joke.
Hughes - I am not familiar enough with contenders pre-2004 so I can't take a good swing at this, he probably has the worst just based on the era.
Win Finishing Rate - This shouldn't matter whatsoever but people like to talk about it anyways. A 50-45 has always been more clear indicator to me than a quick stoppage on who the better fighter is.
GSP - 54%
Hughes - 77%
Usman - 50%