"the people who hire CEOs are the boards of companies and the boards of companies are mainly staffed by CEOs of other companies who unsurprisingly are incentivized to advocate for higher CEO pay."
Imagine a charity or pension fund that invests in a company. What incentive do you think they have to spend money unnecessarily on CEO compensation?
What's so absurd to think that people from one class (CEOs/VC/etc) want to help people from that same class even if it's against the laws of the free market?
If I help someone who kinda identfies with me, it raises the chance that they will help me/my friends/my family in the future.
Because it goes against Occam's razor.
People pay CEOs a lot. Why do they do that?
Likely: because they have to.
Unlikely: global conspiratorial private welfare programme.