FWIW, I have been using Spotify Premium for about 10 years, with 3 last years as a family plan. I decided to switch from it due to their poor remuneration to artists scheme, so moved my family to Apple Music just over a year ago. I quite like it, another family member wishes I stayed with Spotify, the third family member is somewhat neutral and the forth does not care for music herself, as we DJ for her.
What I like about AM:
1) ability to quickly toggle the new (iOS 17.2) music filter if need to play something “odd”;
2) the sound is better in its lossless mode;
3) I actually quite like AM more “spacious” UI, compared to Spotify.
What I liked about Spotify:
1) Wider device and platform support;
2) Better sharing;
3) Ability to switch seamlessly between different devices, so I can start playing something on my iPad and switch over to iPhone at the same spot.
Another worthy contender is Tidal, which actually offers an excellent sound in its HiFi mode and gave me some great suggestions (I literally liked almost every track after entering just three artists in). I just found them lucking with non-English contents (lyrics, etc.) and the app itself looked very sombre compared to AM & Spotify.