Spotify is much better for music discovery. It has better algorithms for suggesting music to you, and better playlists to discover.
Apple Music is better for library mana cement. It supports bigger music libraries, nesting playlist folders, and allows you to upload your own music to your own private streaming library.
Tidal is good for its high-fidelity option, but the average person cannot tell the difference between 256kbps M4A and lossless audio, so I dont think its worth it unless youre playing music through a very high-end system.