No, they are compensated in what is agreed to by both sides - which is not necessarily fair or representative of the part they played in building the business.
Yes, and if they were not made better off by it they would have never agreed to it.
>which is not necessarily fair or representative of the part they played in building the business.
No one is compensated based on what percentage they contribute to building a business or product. That is referred to the labor theory of value and it has been disproven.
As for fair, you tell me what fair is.