We all use labor to meet our survival needs. Humans were just smart enough to specialize in different tasks, and we had to find a way to quantify our labor so we could trade it for different goods.
We don't all need to be farmers, so a doctor will pay a farmer for food, and a farmer will pay a doctor for healthcare. It's a much more efficient way to aggregate expertise in different areas, which means more services are available for your labor without you having to be capable of all of those different kinds of work.
A chimp may be able to feed themselves with their labor, but they aren't making themselves smart phones or performing advanced healthcare. Indigenous societies in North America pre-British are a good example of what humans are capable of without a complex market system to trade skilled labor.