I think they may have had equal fame in America, but globally there was no comparison, look at the response to Ali in frica, no way was Tyson known in Africa like that.
The movie Ali is more compelling than any movie that was made about Tyson, it did far more box-office and had far interest.
Boxing was just as popular as footbal in te 70`s, being the heavyweight champ at that time was the most prized of all sports achievements back then.
IMO Alis legacy and what he did outside the ring makes him more famous. Tyson brought back and catapulted boxing back into popularity when he beat Trevor Berbick. Tyson would be more infamous than famous. 20 year old Mike was the best Mike Tyson.
The fight was watched by a record estimated television audience of 1 billion viewers worldwide, becoming the world's most-watched live television broadcast at the time. This included a record estimated 50 million viewers watching the fight pay-per-view on closed-circuit theatre TV. The fight grossed an estimated $100 million (inflation-adjusted $500 million) in worldwide revenue.
When We Were Kings is frequently regarded as one of the best boxing documentaries ever, and maintains a 98% positive rating at Rotten Tomatoes. The film received strong reviews from critics such as Roger Ebert and Edward Guthmann. It was nominated for the NAACP Image Award for Outstanding News, Talk or Information - Special in 1998 but lost to Dinner with Oprah: A Lifetime Exclusive - Toni Morrison. The film won the 1996 Academy Award for Best Documentary Feature. At the presentation, both Ali and Foreman came up to join the filmmakers to make it clear they had long made peace since that match, with Foreman even helping Ali up the stairs. It was also nominated for the Grand Prix of the Belgian Syndicate of Cinema Critics.