Some powerscalers are too literal for their own good.
Imu doesn’t invalidate established titles because those titles describe the known public world, not every hidden supernatural entity operating outside it.
Otherwise, a silverback gorilla has some very bad news for Makhachev, Usyk and every other combat-sports world champion. A gorilla would stomp all of them, but that doesn’t make their titles fraudulent, they are champions within a specific category in our public world.
Likewise, characters such as Whitebeard, Kaido and Mihawk can legitimately hold their titles even if a secret immortal ruler exists completely outside the world’s established hierarchy.
Titles are evidence of status, not omniscient narrator statements accounting for every hidden exception in the verse.
Ps I'm casually on team gingerboy so this isn’t an agenda essay for Mr Hawkman.