I'm not surprised by the conclusions, I've never seen anyone claim SMART has ever been useful, unless the HDD is already known to have issues that are already noticeable without SMART, SMART just makes it possible to diagnose the actual problem. Though, of course this is limited by my own anecdotal research and personal experience.
What I wonder than, is if sensitive isolated microphones could be tried for this purpose? We already know that sounds (ie yelling at the drive) can vibrate the platter enough to cause performance degradation. If there were internal mics in each HDD recording sound as the HDD spins and correlate that to HDD activity, could that be correlated with failure rate?
If you have spinning drives, monitor the (raw) sector count stats. Add together reallocated sectors, uncorrectable and offline uncorrectable.
If you have good operations, replace when convenient after it hits 100. If you have poor operations (like in home use, with no backups and only ocassional SMART checks) replace if it hits 10 and try to run a full SMART surface scan before using a new drive.
For SSDs, good luck, I haven't seen prefailure indicators.
I've also never found anything meaningful out of SMART at home lab scale. I do know the way vendors report it is a shitshow, so I wouldn't suspect it'd be great training data.
What I'd be really curious to try is run IO benchmarks on the drive and see if there are performance issues that indicate a drive is failing.
I have had drives tell me something was wrong before they developed bad sectors. It does take a lot of monitoring though and probably leads one to replace drives earlier than might be necessary.
SMART Load_Cycle_count told me my WD Red drives were parking heads after a few seconds without use - behaviour you'd expect from WD Green, not WD Red. I hit nearly 100k LCC on all drives in a ZFS pool within a couple of months. When I found the problem I was able to disable the behaviour with idle3ctl.
What I wonder than, is if sensitive isolated microphones could be tried for this purpose? We already know that sounds (ie yelling at the drive) can vibrate the platter enough to cause performance degradation. If there were internal mics in each HDD recording sound as the HDD spins and correlate that to HDD activity, could that be correlated with failure rate?