I will just say that Kazuto Ioka's career is very underrated. Best boxers since the 2000's : Floyd Mayweather, Naoya Inoue, Wladimir Klitschko, Chocolatito, Crawford, Usyk.
In terms of raw athletic ability combined with genius ring IQ and technical know-how leading to a real mastery of the sweet science, and then proven by a career that includes a great variety of top contenders and legacy fights, in which a boxer shows not only ability on the night but also the longevity, discipline, and focus to be able to dominate over a long period of time in a stacked era, I’d have to go with Charlie Zelenoff.
He landed body shots on Wilder despite being massively outweighed, who’s Deontay to tell him what’s what ? Dejon Daniel’s or whatever his name was, Charlie schooled him.