I think you may be missing the point with examples of execs who got paid a ton of money even for mediocre or poor performance. The reason they got paid so much is that decisions at that level are absolutely "billion dollar decisions", in that the performance of the executive, and the executive alone, can be the difference between a super successful company and a failure. That is one reason why execs are paid so much - going in to the deal boards are betting that their execs will be one of the successful ones, not one of the failing ones.

The same is true for "rock star" engineers. I absolutely believe there are a few engineers who can make the difference between being wildly successful or being an also ran. To use a well known related example, consider Jony Ive. I believe that his unique design talents have been responsible for billions of dollars in value to Apple shareholders.