Fundamentally, why do we work? We work for money. The employees want to make as much money as possible, the employer wants to make as much as possible. Management, representing capital, can make more money by paying their employees less. Therein lies the fundamental, unsolvable conflict between labor and management.
By the company as a whole making more money, everyone can make more money. But no matter how much more money the company makes, capital and by extension management can make more money by paying the employees less.