If "things go catastrophic" your hard drive is not usable at all anymore. At the very least some files can't be recovered at all. So you need backups in any case. Once you have backups, you might as well encrypt your hard drives, especially if you store these in different locations (which you should).

An advantage of encryption is that it makes it easier to give away or resell devices. With recent encryption schemes (well the ones on Linux, given this article), I feel confident that overwriting the encryption keys gets me close enough to not leaking my data once I get rid of an old hard drive.

That’s not true. I’ve had many computers that refuse to turn on and I was able to recover the files by removing the drive and loading it into a USB hard drive reader and recover the files.