Audible’s new proposed royalty structure is a slap in the face to authors, readers who care about them, and exactly opposite of what they promised Brandon Sanderson barely a year ago.
It is an attempt to seize a monopoly by punishing authors until they agree to exclusivity, which would drive Audible’s competitors out of the market.
If you are looking to move away from Audible but don’t want to split your library over multiple apps, then you should take a look at https://audible-tools.kamsker.at/
Audible allows you to download your books in their proprietary format directly from the website. The website linked above converts those into actually usable files to put onto your audiobookshelf instance or whatever. Plus it’s all just ffmpeg under the hood. So once you converted one file online to get your 4bit “decryption key” you can do the rest locally
I believe you can also do that in calibre.