I think we are talking about archival storage rather than storage in use. In which case hard drives can last decades.
I wouldn’t trust it that way, no. They might last decades. They also might not. It’s a gamble on any single drive, or even a few mirrored drives.
File system also matters. Modern ZFS has error checking that can handle some level of bit rot. Older formats generally don’t.
If it’s over 7 years or so, I want to get the data off of there.
Hard drives break down from use, not from sitting around. We aren’t talking about SSDs which while they don’t break down will experience data corruption over time. It’s not really a gamble at all with mirrored drives.
You’re also telling me things I already know. I already use ZFS. I agree that you should be using something with data integrity protection. Though ZFS isn’t always what you want for archival purposes.
Magnetic platters absolutely do break down from sitting around. Bearings and other mechanics can also go bad. For those things, a professional recovery operation could still get the data if you’re willing to pay, but the drive itself should be thrown out.
Edit: keep in mind that with bit rot, the drive may superficially function just fine. Your data may even be 99% correct. That 1%, however, could cause unrecoverable problems, such as videos that glitch in the middle.
