Some programmers, maybe, but very few could move large company's revenue by 10%. And almost certainly no one moving physical stuff around in a warehouse could.
Sure they could. They're the feet on the ground, so to say, and so they have the best insight into inefficiencies which are occurring on a day-to-day basis. You can bet it wasn't a CEO who discovered UPS' "only make right turns" trick. Or Bezos who optimized Amazon's warehouses.
A 10% reduction in costs is very realistic for these kinds of finds, and those reduction in costs are worth more than a 10% increase in revenue.
Does the employee get near what they make the company? I doubt it.
Does the company need to pay the employee near what they make the company? No.
So a company does not need to pay the CEO the difference that they supposedly make the company. They just need to pay what someone will accept to do a similar job (I am not saying worse in any way), just like other employees.