I have used Spotify for years and I have used the 3 month Apple Music free trial and even paid for them concurrently this year when I was toying with getting a HomePod, purely to see if I could live with Apple Music.
Whilst the general consensus is that Apple Music sounds marginally better, so marginally that you probably wouldn't notice, I decided to stick with Spotify purely for the Daily Mix playlists, User created and curated playlists and the overall experience using the app.
I found that Apple Music was still stuck in the iPod days where it's very album orientated and I had to put work into finding music that I liked and creating playlists. Whereas Spotify already had 5 Daily Mixes of differing genres ready to go and then when I wanted to create a playlist it would suggest an endless list of similar songs that I could add at the touch of a button.
So, for me, all of these Spotify features far outweigh the ever-so-slightly AAC encoded better quality audio. I really wanted to like Apple Music since I seem to have every other item that Apple sells but I just hated the app.