"Great leaders are like surfers riding a big wave. It's easy to get distracted by the surfer and forget that the wave is really the important part."
I used to think that. I've recanted. I'm still not 100% sure why leaders are so important, but the evidence I've personally seen over the years is pretty clear.
My best guesses are some combination of:
1. It is true that the performance of a team is given an upper bound by both the quality of the team and the quality of the leadership, but people tend to badly underestimate how much quality and talent there is in the world. The average person is above average in some significant way. I would agree world-class results require a world-class team, but I think in general, for a given "random" [1] selection of team and task, it's a rare time when the core problem is a true lack of talent. Don't get me wrong, I'm sure it happens, but I've never personally witnessed it in 15 years. Whereas, I've personally witnessed many teams failing to live up to their obvious potential because of bad leadership. So, in a sort of mathematical sense it is true that neither leadership nor team talent is more important, in practice, leadership is the thing for which demand is much higher than supply, not team talent.
2. It is true the team is who provides the day-to-day progress on a problem, but it's generally the leadership making a lot of little decisions that add up over time; little words that affect morale, small key decisions that affect efficiency by a few percent, that little bit of vision-from-experience that avoids blowing a few days on a bad path, the careful selection of problems to personally take on. It adds up to a lot, and especially when the leadership is blowing these little calls consistently, no team is good enough to undo the damage... especially when the leadership actively prevents it!
I do agree that it's important not to fetishize leadership and never to forget the team gets much credit too, but over the years my estimation of the importance of true leadership has been going consistently up, not down.
[1]: By "random" I don't literally mean five people uniformly randomly chosen from everybody on planet Earth, but something more like, go out to a random company and get a random team working on some problem, and it is unlikely that the most pressing problem the team has is a raw lack of talent to complete the assigned task. Again, totally non-zero of course.