Note that ZFS (and probably other fs) checksums are not data corruption protection, but data corruption detection ;)

If a checksum error is detected, you depend (mostly) on your RAIDZ protection to recover from it [0]. If you're on a single drive or striped array without mirrors or raidz1/2/3... you're SOL. (ditto blocks can help but they aren't the best. I'd only recommend them if you're stuck on a single drive setup without raid)

But you at least know that your data is corrupt, and that's very important too :)

  0: https://openzfs.github.io/openzfs-docs/Basic%20Concepts/Checksums.html