The fact that you don't see how a filesystem integrated snapshot function could make a difference tells me that you've never used anything like that. And your alternative of managing partitions and 'backups' tell me that you certainly have never tried to manage anything like this on a scale beyond your own machines.
Let me tell you, ZFS-like snapshots are the best improvement to computing since proper multi-user systems. It makes managing file security and integrity so, so much easier, and at almost no cost. (and by ZFS-like I mean with the ease and speed of ZFS, I've not yet seen much numbers on BTRFS performance)
If you look really closely it even has a booc!
The optimum committee has no members. -- Norman Augustine