Regardless of one's feelings about Ali/Clay, he sacrificed a lot by not going to the army.
Not a lot would make that sacrifice on our convictions.
(BTW, back then I was a draft dodger too
Not something I'm proud of today)
Without the ban, there may not have been a Joe Frazier, for example.
Ali was a marketing expert outside the ring and injected life into boxing, in general, and the heavyweight division. After him, boxing fluorished in the lighter divisions. Leonard, Hagler and Hearns and even some of the really skinny guys.
Holmes was hardly qualified to carry Ali's jockstrap. Great jab no power.
For two decades Ali was boxing and boxing was Ali