Why are test users not visible to developers in my organization?

I was under the impression that test users are created at an organization level. However, it turns out that only the developer that created the test user can manage them via the 'Test User' tab in the Developer Dashboard. Other developers can't even see these test users (even if they have the admin role).

According to the docs here, test users "Are visible to users with admin or developer roles in the Developer Dashboard"

When clicking on 'Manage Friends' for a specific test user, I can see that there's an 'Owner' property. It's also worth noting, that I actually do have the option to add a test user created by someone else as a friend to one of my own test users. However, displaying a list of all test users in an organization is not possible. Only the test users that I created are visible in the 'Test Users' tab.

I don't see why every developer with appropriate permissions shouldn't be able to do as the documentation suggests and display the list of all test users in an organization.