It's a pretty simple question. It's control. As the owner of an asset, I have control over how I use it. I own a house, I can control what I do to it (within the limits of the outside laws). I own a source repository, I can control what changes are accepted. I own a domain, I can control what it points to. I own a digital soward in a game, I can sell it or I can use it in game.

Ownership has limits, in the real world those are regulated by the government. In the digital world they can be regulated by a DAO. But ultimately, there are benefits of ownership, and responsibilities to ownership.