Apple Music because it doesn’t shove podcasts down my throat. I also prefer the algorithm on Apple Music over Spotify. Spotify is too safe by only recommending music that I already like, while I have discovered new genres that I now love from using Apple Music. Spotify is just too repetitive in my experience. I do miss the Discover Weekly playlist though. That was the one thing that helped me discover new music on Spotify.
Verizon caught on and closed that loophole, so we will have to see whether T-Mobile does as well.
Audiobookshelf works great and is very easy to setup using Docker. I get most of my audiobooks through Downpour. They have a subscription that gives credits to redeem for audiobooks similar to Audible, but they are drm-free. I download the audiobooks and move them to my NAS that has Audiobookshelf running on it. Audiobookshelf has a web client and apps for Android and iOS (TestFlight beta).
They are not ready for regular use yet. Performance is poor and battery life is bad. It’s fun to play with my Pinephone and watch the software slowly improve, but there is no way I could use it as my primary phone.