> i ought to be allowed to produce a clay-tablet version (at my own expense, and only for my own use).

What in the world does this have to do with Amazon providing a feature on their audiobook distribution platform, for which certain licenses were acquired to be able to distribute these audiobooks, that automatically creates unlicensed copies? If you want to create a clay-tablet version from your own copy for your own use, go for it. But the moment Amazon decides they're bored with audiobooks and start selling clay-tablet versions on amazon.com without appropriate licensing, that's entirely different.

Your analogy would mean that you would have to transcribe the audiobook for your own personal use. That would probably be fair use but you probably wouldn't want to do that.

using a tool to transcribe (for example, a tool provided by amazon) is the same as doing it myself.

But is Amazon actually providing the tool, or just its output? Could I use it to transcribe any audiobook I want, even if it isn't available via Audible? Because otherwise it's not you doing it for your personal use, but Amazon redistributing copyrighted content.

if amazon is redistributing the text without providing a way to transcribe your own audio as well, then it is definitely a copyright infringement (assuming they didn't also purchase this right from the copyright holders).

But that doesn't make any sense. If I want to make a legal backup of a DVD I own but don't own the equipment to do so am I not allowed to take my DVD to a 3rd party and have them create a backup on my behalf?

In the USA this isn’t allowed. Neither is backing up DVDs in general though. https://en.m.wikipedia.org/wiki/RealNetworks,_Inc._v._DVD_Co....