>what you actually built is a network for trade that no one controls
That's true in the same sense that no one controls the internet.
People can control their own portion of the network, they can ban peers and report listings to search engine providers. They can create a custom client that will only see certain types of listings.
Distributed networks aren't a new phenomenon, no one controls them either. If someone could control them they they wouldn't be distributed anymore.
There are ideas for governance systems (voting or other mechanisms), but if the network is permissionless then there's really no way to have an effective governance system (that I'm aware of).
What about a network that people could control, but not governments or corporations? That's a technical challenge if I ever saw one.