Fire the CEO markets are Gigabrain. Even if we started with a smaller sample (50?, 10?) it seems like the exact kind of thing that people will discuss, as it can be used to determine the value of a CEO compared to their peers.
It might seem obvious that people will predict Tesla would do worse without Elon, but I'm sure there are some very interesting examples where that isn't the case.
Personally, I'd be saying Google could do better without Sundar Pichai.