Game studios use Unity to coordinate the approximate actions of thousands of employees into a coherent game.

What would happen if you made an instance of Unity and opened it up to everyone in the world?

Would something coherent emerge, or would it just be noise?

Perhaps the thing that makes games built in this internal swarming approach coherent is a shared north star vision that everyone working on it is compelled to share.

If they didn't share the north star they'd have never been hired, or would be fired.

Unity, at the end of the day, produces a coherent app: a point in time, coherent, convergent object that can be distributed in the app laws of physics.

Why does the output of Wikipedia cohere?

Everyone who chooses to participate, and who earns trust and authority in that community, adheres to north star principles that lead to a coherent outcome.