I watch both sports, and although I do have issues with boxing I still accept that there's a relative opportunity for all competitors from all corners of the word to have a shot at a world title. It's not completely equal/fair, as boxers from the US/UK/Mexico have an advantage in terms of titleshots and repeated titleshots which the foreigners usually don't. But the mere fact that there's four titles which are seen in equal light gives people multiple routes, and you're not stuck with a situation with one champ colluding or hogging "the" belt.
But in MMA, it's completely skewed. In MMA, the UFC is seen as king, while Bellator is seen as the second guy. In the UFC, everything is geared towards Americans and Brazilians. There's roughly 66 male Brazilian fighters signed to the UFC, compared to only 23 Russian fighters. And most of those Russians fight once a year. Brazil is great at BJJ, but Russia is great at wrestling, Sambo, judo, Sanda and boxing. They have hundreds of Olympic medals in wrestling and boxing. Brazil has 0 medals in wrestling, and only 3 in boxing (their first Gold won in 2016). So why are there so few Russians, but 3x as many Brazilians?
Then there's Bellator, which has an outright blacklist on North Caucasian fighters. The Russian Olympic wrestling team is entirely North Caucasian. They dominate Combat Sambo and MMA in Russia as well. Bellator having Russians but barring North-Caucasians is like someone allowing American boxers but barring Blacks/Hispanics. How do you bar the dominant contingent?
Boxing is changing its ways, there's more Eastern European and Central-Asian fighters being signed by Western promoters. GGG and Shumenov opened a lot of doors, and promoters are signing Kazakh and Uzbek Olympians and amateur aces. It's only in the last 2 years that Uzbeks have started going pro. Even though they dominated the amateurs for decades. I would appreciate if the UFC would sign more CIS fighters, particularly Russians who dominate grappling and who currently have one of the largest MMA scenes in the world with 4 major orgs and a dozen smaller orgs.
They are grossly underrepresented in the UFC. In fact, from what I gather the UFC doesn't even sign them. It's usually Ali AbdelAziz who signs them, then brings them to the UFC or PFL, whichever of the two takes them. One man can't handle it all, it also means Ali only signs athletes from gyms he's personally acquainted with. There's an ethnic dimension to this as well, which ends up where most of the guys he signs are from Northern Dagestan. Fighters from Southern Dagestan, Circassia and Chechnya have an even less chance of getting in. I mean, a few years ago most of the guys signed were teammates/friends of Khabib alone.