Cloud ownership is easiest to trust when it is written on the resource, not hidden in a chat thread.
An owner tag with a review date gives the next engineer a starting point. If ownership transfers, the tag should change and the commit should include a short reason. That small record saves time later when a permission, cost spike or incident points back to the same resource.
I try not to rely on old messages when checking access. Chat can explain why something happened, but it should not be the only place where ownership lives. If the tag is missing, I treat the resource as unowned until someone claims it in writing.
A quarterly scan helps because quiet drift is normal. Teams move, projects change and temporary resources become permanent without anyone announcing it. The scan does not need to be clever. It only needs to list resources without current owner details and put that list where the right team can act on it.
Ownership is not a label for tidy diagrams. It is the path to the person who can make a decision when the resource becomes important.