If Conor is so good at making money elsewhere that doesn't meant he UFC has to meet those demands. Fighter pay aside, say Conor wants $50M. You think the UFC is going to give him that? If I made $200,000 somewhere else I can't go to a grocery store telling them I need that much because that's what I'm worth. There's only so much certain places can give and the UFC isn't the place for him to make millions upon millions.
And no, the UFC's current practices with all the lawsuits and eyes on them can't lock him in a "lifelong contract". If Conor is making himself too big and outpricing the UFC that's HIS problem.