Audible.com is, for your faithful author, one of the hardest Amazon properties to fully divorce from. For one thing, having someone read to you as you putter around is undeniably one of life's great pleasures. For another, the backlog of books that you have accumulated already (and paid for!) are hard to let go. And finally, the clear environmental or labor harms of buying through Audible are less clear and present than the act of having physical things delivered to your door.
Still, Audible is owned and operated by Amazon, and as such, we've got to say goodbye. Some suggestions for how to replace this tool in your life:
Support your local bookstore! Libro.fm is a great tool, which "makes it possible for you to buy audiobooks directly through your local bookstore. As part of the sign-up process, you’ll choose the independent bookstore you want to support with future purchases and Libro.fm will split profits with this bookstore. Libro.fm is a Social Purpose Corporation making it a great option if you are seeking an ethical alternative to Audible."
Use your public library! The Libby app can do just about everything Audible can do, plus it's free! There are also lots of great apps put together by individual library systems - for example, this NYPL app.
Use the Internet Archive or Pirate things. These are a little bit less user friendly, but you can usually find things if you are willing to dig! This Library Genesis thing, for example, is a deep rabbit hole.
I use rakuten kobo books app, which also has a kindle alternative reading device that hooks you straight up to the full purchasable library. relatively cheap subscription with 1 free book a month. can highly recommend and it's not evil yet as far as i can tell!