But a good partition scheme can make a difference in safety and recoverability from disaster.
I fail to see how. In all the years I've been doing this stuff, I've seen machines eaten up with all sorts of failures and maladies. But I've never once ran into a situation where extra partitions would have made a difference. Either the drive is still spinning, or there are valid backups available ... Or the drive stopped dead, the backups don't exist, and the party in question is quite royally screwed.
15-20 years ago, when a hard disk over 80GB was considered huge, my working computer tended to be a tower with 2-3 drives, and I would back up my system disk by imaging the whole drive.
My working computer for the past dozen years has been a small form factor machine with a single much larger drive, currently 2TB. It is partitioned because I can backup a full image of a 100GB system partition to another partition on the same disk in less than 30 minutes, whereas imaging a 2TB drive, or even a 500GB drive would take many times longer and require an external device.
This means I always have a recent full image backup of my system partition. It also means I never have to reinstall the OS, since I can simply restore from an image, and since the images are reasonably small (<20GB), I can keep a number of them.
I don't recall the last time I had to replace a system disk because of drive failure. Probably not since MS-DOS 5. On the other hand, there have been plenty of times that the easiest way to recover from a software installation gone awry, a possible virus, or just a bad Windows update, has been to restore the last good image of the system partition.