Well, perhaps you don't know your history so well, but MMA has been doing stadium shows for over two decades. Pride regularly had 50,000 in attendance, biggest show was 80,000. The UFC has done stadium shows in Canada, Brazil, Australia, with 55K+. KSW does shows in Poland with 50K+. Boxing has done a handful full of shows that have done huge attendance, but like I said, there is 4 or 5 of those. It's very top heavy and revolves around mega stars in boxing. If you look through the biggest attendance in combat sports history, take the top 100 shows in attendance, boxing only has 16 while MMA has 84. Boxing has 3 shows that did massive numbers 80K + at Wembley, Canalo in Texas which did 70K. But beyond that it falls off drastically, there were a few fights that did 40K-50K. MMA doesn't have the 80K shows, but they have about 10x more in the 40-50K range. And way more in the 20-40K range. Having a few massive shows in Engalnd, doesn't outweigh consistency over 20 years. Like I said, 16 boxing vs 84 mma. And in the 101-200 biggest attendance it continues heavily in favor of mma.
What you're talking about is Canalo who's among the biggest starts in boxing vs free UFC shows on Cable. But you had Khabib pulling in 15 million viewers for his fights. Canalos fights were broadcasted on a national network. Once again, it revolves around one fighter who's a national hero but doesn't speak about the popularity and consistency of the sport and viewership. But if you're talking about viewership, it's not even comparable between MMA and boxing. The UFC does far better than boxing on TV for the past 15 years. And when talking PPV, take the top 20 shows all time, MMA has 11 vs Boxing 9. But then take the next 30, MMA has 26 while boxing only 4. So in the top 50 PPVs all time, MMA has 37 vs Boxing 13. And if you from the 51 to 100, it heavily favors MMA, it's not even comparable.
LOL, those stats are bogus. I know you just googled it and got the first hit. Why don't you actually do some research. The UFC has nearly 600 fighters on its roster, while Bellator has around 300. So you're at around 1000 already. Never mind even going into all the other bigger promotions like and then all the smaller regional ones all over the world.