I love seeing this data analysis. Thank you!

(Is this due to the boosts the top users give themselves when they auto-upvote their posts?)

I think it's partly that and partly the bots run by other whales who are busy and don't have time to curate content so instead they have bots which upvote trusted authors who consistently put out good content. I see that as a good thing and a bad thing, depending on how it's used and how it motivates (or not) authors to continue putting out content which is better than other content out there. I'd love to see more undiscovered talent getting recognized, but that is happening more and more with people being rewarded for doing good "Look at this hidden gem I found!" posts.