The Project Manager basically only backs up *sequences*, right? It does nothing with the bins in a project.
I have a template project for my show. It has a bunch of important resources - like stock sfx, music and dialogue (efforts, etc) - which don't live in any particular sequences.
I would like to create an archive of this template project, which would pull together copies of all the resources I've accumulated over time on this show - which live in bins, not sequences - in the same way that Project Manager would pull together copies of all the elements used in a sequence.
That's easy if the source media for 'all the important stuff' is stored in one place, and will be there a year from now when you need it again. That's not the case here, where the source material are clips from nearly a hundred episodes which will no longer be in their original locations (or even available at all) the next time this project file is needed.