Deletion is very much a technical/organizational challenge. Imagine some engineer writing some feature you've never heard of and they decide they need data in

Deletion is very much a technical/organizational challenge. Imagine some engineer writing some feature you've never heard of and they decide they need data in a different format. They write a job to do this. Now imagine that job somehow has a bug which prevents the deletion system from understanding that copy exists. That bug could be non-obvious to find.