Let's be serious. Shaq doesn't have multiple MVPs because he slacked during the regular season and didn't keep his body good during the off season. He pretty much coasted back onto game shape until he got dominant in the playoffs. Healthy Shaq was, by far the most dominant and best player around in his prime. But he was notorious for coming into the season out of shape.
Kobe was the best player in the league in 05 and 06. His team was garbage but he was still The most unstoppable scorer around. That being said, Kobe's was never as dominant a player as Shaq, Jordan, Lebron, etc but Kobe's longevity and consistency cannot be denied.
Duncan's ability and affect on the game go beyond box scores. Duncan is a GOAT level defensive anchor with the likes of Russel. Kobe's intangibles in scoring that don't show up on box scores (versatility, confidence, etc) can be compared to what Duncan does for defense.
Being Shaq's sidekick is not a knock on Kobe. He was still one of the best players in the league but Shaq was just that good. But people also need to stop comparing the Shaq that 3-peat to the Shaq that Wade and Bron played with. They aren't even in the same tier of ability.