A lot more than me, but that's not him taking my wealth. I'm in a voluntary relationship with his company, I've agreed to my salary, and if I'm unhappy with my pay, I'm free to find other work.
You can't count the upsides for the shareholders without counting the downsides as well.
That's not to say that investors shouldn't be compensated for their initial risks when an actual funds injection is required, mind you; but them being compensated ad vitam eternam - and more generally, them actually owning the structure - makes very little sense morally for me (and beyond "morally", I don't see how this can result in anything else than progressive concentration of wealth society-wide in the long term).
You also assume people can "move on to another job" without too much trouble; again, that may hold true in tech or similar popular domains but it's far from true for a lot of people.
>I'm free to find other work.
A corporation is a model of communist dictatorship. The higher-ups control the means of production, they take your labor according to your ability and give to you your need (as determined by them.) In the sense that existing in a communist dictatorship is 'voluntary' then your work for the company is voluntary. And in the sense that being able to move from one communist dictatorship to another communist dictatorship is free then you are free.
That explains why communists revered Marx! He explained to them how it all works!