Fighting, whether MMA, Muay Thai, Kickboxing or Boxing, is an interesting career pursuit. It is not like other major sports, where viewership is massively based off of fans love for the sport. Now don't get me wrong, there are those 'hardcores' who will watch no matter what, but for a fighter to make millions they have to have that extra something. We can break these down into three things, charisma within interviews, trash talking of opponents and a fighting style that captures the eye.
If you do not have even one of these then your chances of making boat loads of money are highly diminished, even if you are the best in the world at your division. Now try to show me another sport that has a similar outcome. Kawhi Leonard was one of the worst interviews in the game, and his style, although massively effective, is not as eye capturing as almost any other top 10 player in the NBA. Yet he makes an incredible amount of money because he wins, but winning is just not enough in fight sports, where dollars earned are massively effected by pay-per-view buys.
What we are really talking about here is the 'it' factor. No one can really describe what 'it' is, but we can 100% see when someone has it. Outside of the ring or octagon they are captivating, they draw you in, making you not want to look away. Inside they have a fighting style that is closer to performance art than the brutality of combat. The question becomes, what turns the connection of a shin bone or knuckle to a cheek bone into an art form that allows us to view them with the 'it' factor. I believe the answer to that is fluidity of movement, is a fighter straining to get their foot high enough to reach the head, tensing up to throw every punch, are they are mechanical in their movements, do they only understand the ABC's of striking but can't string them together into sentences.
Everyone we would currently consider stars or up and coming stars have an aspect to their style that is fluid. In boxing its guys like Josh Kelly, Floyd Mayweather, Tyson Fury, Ryan Garcia. In MMA its Israel Adesanya, Khabib Nurmagomedov, Sean O'Malley, Conor McGregor. In Muay Thai and Kickboxing its Tyrone Spong, Gokhan Saki, Saenchai.
These fighters movements make it look effortless, almost leading you on to think that fighting is in fact that effortless and you could do the same if you really tried. But you can't, these guys studied the ABC's, making sentences is basic to them, they are past making simple haiku's, these fighters are creating music that matches their poetry to the beat of their feet and to their opponents movements. All while understanding and taking into account their surroundings.
They understand the 'rules' of fighting, bring your hands back to your face, don't cross your feet, keep your chin down. But they have a level of understanding and experience to where they can bend and break these rules at will, to appease their strategy in the moment and create.
Now this is not to say that every star ever was or will be fluid, but if you don't have a style that captures the eye through the fluidity of your movements, then you better have both of the other two factors.