I've seen the issue with wealthy enough employees at all the startups I've been at too. Once you get people who no longer feel a certain hunger, they lose ambition and direction quickly. I've seen it happen as startups go from mildly successful to unicorn. Where the founders were able to cash out enough to buy a house in the bay, they suddenly were way less eager about being acquired or IPOing. And I've seen it with people who are on the tail end of their careers, exiting one startup with a very sizeable amount to enter another. The hunger is gone for them, they're just coasting, and they don't seem to have any real reason to even be working beyond avoiding boredom in retirement.
And the worst part is that it feels like these types of people are way too well represented at the top of the hierarchy. The part of the hierarchy where these attitudes matter the most!