ZFS has been around for a very long time (more than 10 years now), and although Btrfs is the future filesystem for Linux machines, ZFS has its own significance. It was the first filesystem to implement many features to help protect data from getting corrupted.
But, although some distros have started shipping Btrfs, it’s still relatively young. ZFS, on the other hand, is quite mature, and if you are looking at setting up your own drives with a filesystem that is capable of healing corrupt data, then you should be looking at ZFS.