That essay seems to be essentially “hardware already does it”. If you go and read the original ZFS paper, much of the reason it exists is they found hardware lies its ass of. Hardware does not lie less since them, it lies more (witness WD recently caught essentially laying about Reds).

And SMART tells you that a disk is dying, it doesn’t tell you the a disk is not dying.

Furthermore the disk health tools can’t catch e.g. a dying cable.