AI can replace people at a low level because they are seen as a cost. While people at the top are better connected.
CEOs travel a lot, probably subscribing to 100 mastermind groups where CEOs of other companies also hang out, playing dozens of mind games and strategising all the time.
Such people are hard to replace. The average employee's role is finite, and they aren't taking much risk; therefore, it's trivial to get rid of them.