Chris - thx so much for the quick reply. I somehow suspected this would be the answer.
I looked at the automation and I recall looking at this before - I forget the issue, but I remember it had a limitation that prevented me from using it.
As a feature request, it would be great to have a deeply nested duplication function, where every child object is duplicated along with the parent. I know that gets tricky, because of the many ways child elements can be linked to a parent.
And in workspaces that are highly-connected, duplicating an entity AND all its linked entities AND all their linked entities, etc. could result in a cloning of a large subset of the content of the workspace.
There are definitely some concrete use cases, but solving them intelligently without causing more problems is not as easy as it first appears.