For certain directories (e.g. his own documents or /etc/) it would be nice to know who changed what and when (e.g. in /etc/) or to be able to got back to any older states (e.g. for own documents) by means of underlying system functionality so that it always works regardless of whatever features in whatever applications.

I noticed gitFS https://www.presslabs.com/gitfs/

I have zero personal experience with gitFS but perhaps this is an interesting project so that it makes sense to get gitFS support in SUSE?