Hewson
Blue Crack Supplier
Comparing achievements in different sports and different eras is really difficult.
I’d vote Jordan for a mix of his achievements + the wide appeal of the sport (e.g. vs the unknown cricket of Bradman or limited appeal boxing of Ali) + the massive cultural effect. Sure, that’s a credit to Nike and NBA marketing as much as it is to him (and his rise was timed perfectly with the rise of globalization), but there was no athlete in the world that came close to him in the 90s, fame and adulation wise, and his appeal went really wide, well beyond existing basketball fans.
Boxing had a Jordan, but boxing never was and never will be a wide appeal sport and Ali wasn’t exactly universally popular at the time.
Jordan wins for both dominating a sport with wide, global appeal, with multiple wins across three peak competitions (college, NBA, Olympic – not to mention the shopping list of personal achievements and records within those competitions), and because of how that dominance was translated into a sporting cultural force unseen before or since.
I think Ali is getting overlooked just because of the passage of time. In the 70's, boxing, specifically heavyweight boxing was hugely popular worldwide (you'd think someone with a screen name like Earnie Shavers would acknowledge that ). And Ali was the face of it, he was by far the most recognizable athlete on the planet, was a polarizing figure to an extent with his antics and anti-war stance, but everyone knew him and had an opinion of him. The Ali/Frazier/Foreman battles were massive events worldwide (Thrilla in Manilla, Rumble in the Jungle), had the internet and ESPN been around, Ali's popularity would have eclipsed that of 90's Jordan tenfold.
He's still one of the world's most recognizable figures 3 decades after retiring and while being ravaged by Parkinson's.