One of the surprising things I heard about last year was that the newer basketball cameras that record all aspects of play rated him as one of (maybe even the) slowest players in the game. Of course, if you've ever watched him run, especially on a chase-down block (such as the one he did in the 2016 NBA Finals game 7), you'd know he's one of the fastest players in the league. However, he's figured out ways to be effective without moving that much so he preserves energy.
At age 33 last season, he played every single game of the regular season, plus 22 playoff games. He's made the NBA finals eight years in a row, which would be roughly the equivalent of 2 additional regular seasons, though playoff basketball is substantially more physically demanding, so the physical strain would be more than just 2 additional seasons.
I think ultimately, the longevity of his dominance, coupled with how talented the rest of the league has been during his tenure, will be the factor that makes him the best player of all time.