People where mostly growing food for themselves and their family, not for each other. This changed when the first basic forms of capitalism where invented, things like markets, guilds, and skyrocketed with industrialization.

No other system that we tried ever worked as good and produced so much peace and prosperity like capitalism. Is it perfect? Fuck no! Nothing that involves humans could ever be. But it is the best we have from a bunch of broken and fucked up systems.