Sure, it'd be great if the fighters made more money.
But if they're in the UFC in the first place, is because they need (or just want) the company to organize everything surrounding the fight, including broadcasting, advertisement, matchmaking, and probably a lot of shit I can't even begin to think of.
If they feel that fighting in the UFC is definitely not the best or easiest way to get rich, I'd advise them to leave when they can and instead do the easiest thing.
Because I doubt the UFC would suddenly become a philanthropic organization.
I'm not even being sarcastic, they should do what's best for themselves, without irrealistically expecting their surrounding to change.
I actually feel for the fighters that have to keep fighting for as long as they can, because they have no other marketable skills. That's not a job you should do for that long.