Yesterday I realised same and wanted to ask listing reporting feature.
Maybe its not archaic. But it depends on the scale. If you have 100's visits per day and only a few new ads daily dont expect this to be used.
But if you have 1000's visits a day with 100's new ads daily there alway will be something not right and someone will always be bothered to report.
I think it should be implemented in simplest possibly way.
Just the link 'Report this listing' with small modal window on which a few reasons for reporting would appear. Then when choosing the right reason user should see 'Thank you' message and automatic email should be sent to admins containing reported ad ID.
I have been using Patricia theme before and I do like how reporting option was implemented there (small megaphone icon with the drop down list on mouse hover).