If music discovery, using the service on multiple devices, and sharing playlists with others is your priority, definitely go with Spotify because those things are either non-existent or really limited in Apple Music. I think which service you use depends on how you use the service and what things are more important to you. Again, if you're listening to music on more than one device and like to seamlessly move between devices, this is a fantastic feature. This feature is a killer feature if you listen to Spotify on more than one device and aren't completely in the Apple ecosystem. I love that I can play Spotify through other speakers and devices but control it via my iPhone. Apple Music dosesn't have anything comparable.

This is one of the BIG things that always draws me back to Spotify. On the other hand, I HATE all the annoying popups and promotions Spotify has for podcasts. On one hand, I love that I can mix up my queue with both podcasts and music. I will admit I have a love/hate relationship with podcasts in Spotify. I really enjoying queuing up a bunch of songs to listen to throughout my day. Queuing music is (IMO) better than it is in Apple Music. I can always find some sort of new music or playlist, whether it's finding a playlist someone posted here on Reddit, searching for a particular genre or year, or just randomly searching within the app for a new playlist. Music discovery is much better compared to Apple Music. It's easy to see titles to songs and such. The fact that it doesn't have podcasts integrated is sometimes a pro and sometimes a con. It has Lyrics!! I realize this shouldn't be a big deal, but with Spotify we're still waiting on lyrics. It's easier to find music, manage the music I've saved and downloaded, etc. It's really nice and has dark/light modes. Here's my perspective from having used both side by side: I've been primarily a Spotify user but have intermittently used/tried Apple Music several times this past year or two with the intent of possibly switching to Apple Music.

Apple music vs spotify subscribers 2020