I don't know, but in my personal three decades of experience "inevitable disk failure" is not a "tiny subset of risk factors."

RAID is huge defense for keeping "inevitable disk failure" from turning into "massive data loss."

Do you, personally, test backup and restore of ALL of your data that you care about at acceptable loss intervals? Are you sure?

And if your acceptable loss interval is "zero," then redundant synchronous storage across devices in one form or another is all there is.

Backup is a total real-world solution to data loss like antivirus is a total real-world solution to malware and infosec.

If I compare the amount of data I could have lost (or have lost) over the years, non-existent backups would have been way more fatal than non-existent RAID.

My post was maybe to strictly worded, RAID is nice and helpful, but it was responding to a claim that it is irresponsible to advertise a non-RAID device for important data, which is IMHO irresponsible itself, because it suggests that's all you recommend relying on.

> it suggests that's all you recommend relying on.

No it doesn't. Defense in depth is a thing.

I dunno, hard drives stop working basically at random in my experience. RAID is extremely helpful if your device is physically safe and not prone to infection.

Plus, there's only so much you can back up to the cloud. I'd back up 125GB of personal pictures, but not 1.25TB of ripped Bluray media.

Local backups are a thing. Even just having second disk in the same system is much better than nothing (comparable to RAID1 but at higher level).

Local backups are a pain. RAID is advantageous for multiple reasons.

both are needed in the end if you want to be full covered.. backup will cover human errors (ops I deleted the wrong file), RAID will cover hardware failures

having only one of the two solutions will expose you to some risks