Boxing has so many problems with it that it either needs a whole new reboot with a new league that tries to fix it's problems, but then adding a new boxing league is just adding to boxing's already existing problems because it has far too many leagues. WBO, WBC, IBF, OBF, Top Rank, OPB, etc. It's just too much.
But there are far more problems with boxing. First you have no big name boxers. Mayweather and Pac are both old and may draw from name alone, but they fight once every 4 years. That's the other thing wrong with boxing, they only have one big fight every 2-3 years, if that. It's ridiculous that it seems a champion has one fight once every 4 years. Who cares at that point?
UFC has done a smart thing. They push their product now every Saturday, with like 3 different levels. PPV (Big fights and plenty of them) ESPN+ which has big fights, but not as big as PPV, and then they'll throw out just some random fight night, which isnt anything to get excited about, but it's getting their product on TV for people to watch. Boxing doesnt have this. Boxing PPV's or big events are like lunar eclipses. They come around every so often and when they do it feels big and it's a neat event, it happens and people talk about it for a bit afterward, and then poof, it's gone until it comes back around again.