Sure—and I'm serious that I'm open to the possibility that something actually did change about the business landscape for non-shitty (i.e. not corruption or principal-agent-problem) reasons such that it's in fact true that there's a big advantage to hiring from the small pool of acceptable CEO candidates that justifies giving them entire train cars full of cash, but it does seem to me like we didn't used to operate that way and things were... basically fine. Not that there weren't huge advantages to being in the "right" set, or whatever, as there has been in any time and place, but that it seems like for the specific case of CEOs it used to be more acceptable to train up existing employees, who didn't start their employment with the company somewhere in the top-exec echelon, into those kinds of roles, which behavior seems like it would act as a pretty effective relief valve on CEO comp getting out of control.
What's going on now sure looks like what would happen if the people in charge of hiring for these roles had a strong interest in keeping the compensation extremely high. But it's still possible there's something else going on, and there are good, non-corrupt motivations at work.