The cumulative point of this thread seems to be that they are getting to work with 75% of 90% of the audible book market (you claim books are available elsewhere = 25% commission).
You can call that whatever you want, but it sounds a lot like the descent to pre-Internet situations that weren't markers of stable quality and that many people who survived the 1980s don't want to see again.
They have 90% of the audio book market, likely. They do not have exclusives on that much, though. I'd hazard that 90% of the available book market is through the major publishers, still. At large, this makes sense, as most books are still written with upfront payments from publishers.
I would also not really shed much of a tear for Audible. I just don't understand the idea that getting rid of them moves us further from the old style. Seems more likely that the publishers would brow beat any future entry into the market so that it was much closer to how things were in the 80s and 90s.
You can call that whatever you want, but it sounds a lot like the descent to pre-Internet situations that weren't markers of stable quality and that many people who survived the 1980s don't want to see again.