Your point 2 is spot on. Saying hierarchy affects income the most is bad analysis because hierarchy is obviously highly correlated with income. This would only

Your point 2 is spot on. Saying hierarchy affects income the most is bad analysis because hierarchy is obviously highly correlated with income. This would only be news if the author got the opposite result they did. It would have been way more interesting to see an analysis on what hierarchies are net positive for society (i.e. competence hierarchies) and what hierarchies are net negative (probably coercive hierarchies where there is not enough competition so there is market power being exploited)