I think OP's comment is different. It's demand-side, not supply-side.
If a CEO causes 1000 employees to be 1% more efficient, that creates the same value as 1000 employees each being 1% more efficient. Ergo, if I'm an investor, if I believe a CEO will be slightly better than another CEO, it makes sense to pay a lot more.
If I have a market of 7 billion people in the world, and my software saves everyone a dollar, I've created $7E9 of value in the world, and probably monetized $7E7-$7E8 of value for myself. 40 years ago, my market was the US -- roughly 300 million people. With globalization, it's 7 billion.
If I'm making a search engine or webmail client, it's winner-takes-all. If I can hire two engineers, and I believe (statistically, per my lousy interview process) that one is 1% better than the other, I'll drop a shit-ton of money to hire them. See Mythical Man Month for why hiring an extra person with the "saved" money doesn't have the same effect.
And so on...
Economies of scale, winner-takes-all-markets, and zero marginal cost goods like IP fundamentally push salaries at the top up, even with small differences in performance, measured with noisy tools. I've worked with many CEOs. Someone who makes $10M isn't necessarily brighter than someone who makes $100k, but the demand-side economics still work out that way. The $10M salary often comes down to signalling; they've managed a big organization before, they have a nice elite university brand stamp, or they felt better the day of the interview. It STILL makes sense. My expected returns are STILL higher.
Where things break down a little bit is corruption and misaligned incentives -- lots of places, if you pay more, you get less -- but I think that's under-acknowledged. Things also break down is Simpson's Paradox. Globalization means income inequality WITHIN countries is getting worse, but worldwide, is getting better.