Capitalism doesn't mean competition over co-operation. It simply means that you don't have to co-operate if you don't get equal rewards, or if you don't get rewards proportional to your effort. People hate to co-operate if someone else gets the rewards. People love to co-operate if they get a fair share of the rewards, which is what happens under capitalism.
Owning stuff leads to trading and markets, which leads to the law of supply and demand and the price system. Just by looking at prices of things, people can make rational decisions about what to produce and what to consume. People are pushed to produce things that are scarce and expensive, and they are pushed to consume things that are abundant and cheap. This is a form of self-organized co-operation, where everyone co-operates automatically by just acting rationally. By looking out for themselves, they help allocate resources for the whole community. The lack of this mechanism is one of the major reasons why totalitarian socialism fails. See: https://en.wikipedia.org/wiki/Economic_calculation_problem
I'm going to noodle over that distinction of natural capitalism versus forced socialism.
I'm thinking along the lines of family-level (and maybe extended to friends and family / cooperative small village) socialism is natural, but on a societal level, of the scales we see today, capitalism is natural. Cooperation versus competition. Very interesting.