I feel like you're suffering from some sort of confirmation bias.
I've worked under a top talent CEO, and the company collapsed. He made some gambles and they just didn't work out. I am not convinced that a third-rate version of him would have done significantly worse.
Is it just that the company collapsed? The third-rate version of him probably would have ended up in jail a-la SBF or Ms Holmes, with hopefully no one getting killed or maimed, or chemicals in a factory causing cancer across neighborhoods or poisoning wells or something.
There are things worse than losing your job.
Only truly exceptional executives can be SBF or Elizabeth Holmes.
There's also Madoff.
Or maybe the third rate version would have made different choices, and those may have due to pure chance worked out well for us.