And its not just with start ups. People who are more closer to work, generally tend to maximize returns for themselves above those are who are away from it.

This is true even in Big companies. Most product managers I know barely contribute anything to the product, most of the times its the engineers doing all the work and the product manager is just there to provide the validation 'This looks fine to me'.

There is a good reason why carpenters, plumbers, drivers, <skilled_worker> generally do better on the longer run than the supervisor ever does.