If a disk is encrypted, you don't have to worry about the contents if you eventually have to RMA or dispose of the disk. For this use case, it makes no difference how the encryption key is input.
Encrypted data are noise now, maybe, but may be decryptable in the future with advances in computing.
So all this depends on what you worry about.
I'd guess the most common scenario is for someone giving away the entire computer, not fiddle with components. Or theft of the full machine.
This feels like one of those half-security measures that makes it feel like you're safe, but it's mostly marketing, making you believe *this* device can be both safe and easy to use.