As a ZFS user: quite useful. I’ve had numerous of cases of corruption repaired by routine scrubs. Almost every other filesystem (btrfs being an exception afaik) would have been none the wiser.
I would argue though that at this point most other filesystems have this, but they're not as ergonomic/obviously built in. LVM has integrity checking at the volume level (if you give drives to the pool instead of giving the pool an already-RAIDed device), mdraid has dm-integrity. The options are there but not quite as discoverable.
Also note that hard drives have had internal error detection and correction codes for decades, so SSDs doesn't change things much. Probably most checksum errors are misplaced writes and missing writes.