I think you missed the point, also it isn't 'bank managers' earning that amount. It has nothing to do with hours worked either, just revenue generated in most cases.
There was a guy at a previous firm I worked at who sat a few rows in front of me and used to come in at lunch time, sometime days he'd work for 8 hours other days he'd only work until 5... he was earning a couple of million a year and was only in his 20s.
You're talking as though people are merely appointed to certain jobs, that you could find any number of people to fill those roles and simply decide to pay them less. Maybe to put it in another way what you're proposing is that some premier league team sacks their top players and instead brings in a bunch of lower division players to job share/split the multi million pound salary between them and take it in turns to play in matches as one of the strikers - do you not see how that team might then easily be relegated and lose a lot of revenue? Like there is actually some value in having top strikers which is why they're paid so much in the first place?