Backup system is not a VCS, and I am not trying to equate them in any way. I am just explaining where I am coming from; I have a long history with coding and VCS systems.
I hope this helps.
The difference between Git and all its predecessors is that the traditional VCS tools hold file versions as the primary objects and derive the history of a configuration from file versions. This derivation order has been traditionally motivated by performance aspects, but is often incomplete or otherwise flaky. This is where Linus Torvalds turned the tables quite completely. In Git, the version of a configuration is the primary object, and if one needs at all to see the version history of a file (as a tree or some such presentation), it can be derived from the history of the configuration that contains the file, but the derivation process is not always unambiguous.
So which is more important, the history of the whole configuration or the history of its individual files? In VCS, the configuration always is more important.
When it comes to backup sets, the individual files usually are more important than the state of the whole set, but not always. So now I will have to figure out what I actually need.