We see this with Amazon Music offerings as well. Focus on acquisition and accumulation, not innovation.

For Books, Amazon has (1) Kindle, (2) Kindle Unlimited (... a direct competitor to Audible), (3) Kindle Vella (somewhat of a Goodreads competitor), (4) Audible, (5) Amazon.com (retail), (6) Prime Reading, and externally (7) Abe Books, (8) Comixology, (9) Book Depository. And then there are Children's versions...

For Music, Amazon has (1) Amazon Music Unlimited, (2) Prime Music, (3), Amazon Music Free, (4) Amp, and has just acquired (5) Wondery.

I'm cool with checking out audiobooks from Libby, and whatever music app opens consistently when I want it to (i.e., not Amazon Music). Support your local libraries!