Labor is the source of all profit. How would the company make money if no one did anything?
Charge the customer more for the finished product than what it cost to produce it. Obviously.
The simple fact is that if employees were a source of profit, businesses would all try to hire as many people as they possibly could, because not doing so would literally be leaving money on the table for no reason. But obviously that is not what goes on. When a business is in trouble financially, what's more common, a hiring freeze, or a hiring spree?