In other words, Astaire's talents were roughly similar to Michael Jackson's: great dancer, pretty good singer.
But, jeez, look at the difference in their careers and lives: Astaire lived to be 88, exemplified the concept of growing old gracefully in how he slowly wound down his show biz career, enjoyed a decorous private life devoted to his family and his grown-man hobbies (horseracing and golf), and left behind an enormous body of creative dance work in his movies. With Astaire, there's no single peak that overwhelms everything else.
Astaire didn't write songs, but Jackson, who couldn't play an instrument, wasn't particularly fertile of melodic invention, either: even "Billie Jean" succeeded because of an enormous amount of production effort -- it was mixed 91 times -- that went into making it sound minimalistically under-produced. Jackson would have benefited from the pre-Dylan assumption that singers didn't have to write their own music.
For Michael as a dancer, what to do we really have? The live "Billie Jean" on the Motown 25th Anniversay show, the "Beat It" video, and a few other peaks, but most everything else is overshadowed in the build-up to or let-down from 1983.
One of Jackson's career problems was that, unlike Astaire, he appeared in only one real feature-length musical movie, The Wiz. Our popular culture had largely lost its ability to make musical movies. In contrast, the lightweight musical comedies of the 1930s provided Astaire with an established genre, routine frameworks within which he could repeatedly exercise his genius without worrying too much about script, acting, the Meaning of It All, etc. The studio system took care of that kind of thing. (Berry Gordy modeled Motown on 1930s Hollywood studios, and had remarkable success that has never been surpassed, but the cult of authenticity makes that impossible to reproduce in pop music today above the teenybopper level.)
Musical comedy movies gave Astaire a reason to get up and put in a hard day's work doing something he knew how to do. He didn't wait around for inspiration to strike him; the inspiration would come during the drudgery. Astaire was by no means psychologically bullet-proof. He was insecure and used his inner nagging voice to push him to constantly revise and improve his dance sequences. But then get up the next day and start on the next one.
The more ambitious genre of musicals that Rodgers and Hammerstein introduced with Oklahoma in 1943 were a great leap forward aesthetically, but perhaps they began to introduce that note of megalomaniacal artistic ambition into American pop music -- notice how, say, Leonard Bernstein was permanently stuck by his inability to top West Side Story -- of which Jackson's later career was a sad exemplar.
Unlike Fred Astaire, Michael Jackson didn't have any kind of framework. Astaire was a craftsman who happened to be a genius. Jackson was a genius for about six months at age 25, and spent the rest of his life having people tell him he was a genius.