The Jordan analogy is pretty apt.
Jordan had all of the natural ability in the world, but what set him apart was the fact that in a league full of ultra-competitive people, he was the most competitive by a factor of 100.
Paul obviously is an amazing natural musician, but he was also always driven just to do more, more, more and push boundaries, evolve... or, as he put it, "accomplish something every day."
On a different note, one of the most enjoyable things in the documentary is just watching Paul and John goof around together. I feel like so much of the "narrative" of this point in the Beatles career is that they were was all of this animosity going in different directions... and there was obviously some of that... but these guys were also lifelong friends and I think so much of that was overblown.
You can really see it when the two of them are just playing music together, fucking around, laughing at each other's cheesy jokes, etc. So fun to see that.