Justin Gaethje can finally call himself the undisputed UFC champion, but questions of retirement remain.Entering the white house to represent his country in front of the president, 'The Highlight' produced yet another unforgettable night under the lights. Up against the odds, which has become a familiarity, the Arizona native entered the octagon against an undefeated global superstar responsible for some of the biggest knockouts in recent history, Ilia Topuria. However, that didn't faze the 37-year-old, who dominated and earned a corner stoppage victory ahead of the fifth round, securing UFC gold.With the title victory, there's not much left for Justin Gaethje to accomplish. With retirement rumors persisting, Gaethje has a choice to make. Fellow UFC great, Georges St-Pierre, believes retiring on top is the route Gaethje should favor at this stage of his career."He's the kind of guy that works really hard and he comes back from adversity," St-Pierre said. "It's really inspiring to see what he has accomplished."In addition to being the undisputed UFC lightweight champion, Justin Gaethje has been a two-time interim UFC champ and has held the BMF belt following a knockout win over Dustin Poirier.Gaethje's spoils of war are Hall of Fame worthy alone, but it's his bonus earnings that set him apart from his peers. Since arriving in the UFC in 2017, nobody has come close to his 17 post-fight bonuses. Astonishingly, Gaethje has the third-most bonuses in UFC history, behind both Donald Cerrone (18) and Charles Oliveira (21), despite competing over 20 times less than the pair.Having achieved as much as he has, Georges St-Pierre believes there's no better time for Gaethje to leave the sport."You might not like what I'm going to say, but if I were himbecause I like him[I would retire]," St-Pierre continued. "I heard Demetrious Johnson say it, but that's what I would do. That would be an amazing ending. What else does he want to accomplish? He did it all. He did it all."The decision to retire continues to plague MMA fighters. Unlike boxers, those competing in a cage have a harder time bringing an end to their careers for financial reasons.Fighter pay has long been a discussion among mixed martial arts fans, with the company facing widespread backlash over the decades of its existence. Justin Gaethje recently suggested that the UFC create a new company and grant him equity, believing he deserves support from the promotion.Gaethje's pursuit of long-term financial stability and passive income in a UFC-owned company that doesn't exist has raised suspicion among fans about his financial situation. If money is an issue, as it has been for many before him, Georges St-Pierre speculates whether that could be a key factor in his prolonged career in the octagon."Of course he will, you know, for money, if you stop now, you are under the impression that you're leaving money on the table, maybe," St-Pierre proceeded. "Because you're fighting for a title. I'm sure he can still beat a lot of guys. Maybe he can still go on a roll because he still can do it. But health, I think, is the priority, and also the fact that man, when you're a professional athlete in combat sport, it's very hard to retire on top because you're always tempted to see, oh, I can do one more, one more, one more, one more, one more, and you probably can do.""But man, what a magnificent way to end a career it would be for him."Listen to Georges St-Pierre's thoughts on Justin Gaethje and more in the video below.