>There is not really a UX flow apart from telling the user to recover the file from backup.

I agree with all your points, but just want to offer a possible UX solution:

Since the vast majority of data on people's hard drives are video and images, where minor data corruption results in (in most cases) just visual artifacts, we could have a pop-up dialogue that says: "A higher quality version of this file is found on your backup. Do you want to restore it?" when the corrupted file is a video or image and there's a confirmed backup of it.

If there's no confirmed backup then just silently ignore the corruption since the user won't notice anyways.