When and why to deprecate filesystems

Nothing that is not automated is a real backup solution either. At the *very least* you need a backup and an offsite backup that's being kept up to date (and an offsite backup that's actually offsite and disconnected, and the two swapped occasionally). Without that, one electrical storm and you might well lose everything, all at once.

Personally I'd be lost without historical backups as well -- ever so often I find I need something "as it was before Sep 15 last year" or something like that, and with proper backups you can get that sort of thing in minutes. This is not even hard. All the tools exist: all you need is a bit of scripting and a cronjob.