@Hydrogen. I agree with your comment on Ronda Rousey, but Cain and Jon have their own issues like chronic physical injuries and brain damage in the case of Jon hehehe. They would be dominating their divisions if they did not have them.
About Conor, his career is far from short. I reckon we will see something special on April 7 after the Tony versus Khabib fight.
And maybe the toll of grinding it out for the rest of their career as catching up with them like want Cain undergo. As for Rhonda and to a certain extent Jon, perhaps its really hard to maintain the top spot and once you taste defeat in case of Rhonda everything comes crumbling down. As for Jones, hard to speculate might maybe it has something to do with the brain damage he incurred during his career. LOL. As for Connor, I read that he wants to fight Floyd whether in the Ring or Octagon, or a Diaz trilogy or waited it out and get the winner of Tony vs Ferguson. There are a lot of options for him, sky is the limit.