I think the surgerys and the fact that Reem was too much for him made the decision easy for him. He's not the type that would accept a gatekeeper role, and didn't want to put in the time and effort to get back to the top. Whatever the reason its a big loss for mma, he had star power for sure.
it wasn't the surgeries, he just doesn't like to get hit or dominated
he's a bully type of fighter
If Lesnars punching bags had arms he wouldn't even have trained mma 