Spotify vs. Apple Music vs. Google Play vs. Tidal: Which is Best

Agree with loomis. If you listen on hi-end audio, Tidal is IT! While I'm waiting to buy a new main system, I stream Tidal from my desktop (Tidal desktop app) in my office to KEF X300As. FANTASTIC sound.

One more Tidal thought. They desperately need to up grade their interface (at least the desktop app, which is all I've used). You need to be able to search YOUR created playlists (not just theirs), and another big problem I have is that when you use the "back" arrow to go back to your playlist, it takes you to the top (or somewhere in between), but not to where you left the playlist. VERY ANNOYING and time consuming. Bad Tidal! :-(

For the best SQ tidal is it. As for the interface,I use roon, also a no brainer 

I had both Tidal and Spotify for about 3-4 weeks and I noticed that Tidal sounded a little smoother on remastered/old recordings and no difference with newer digital recordings. Spotify seemed easier to manage but I am sure, with time and practice, both would be same. Using Cat8 eathernet cable made dramatic improvement overall. For money, I think, Spotify does good job. (Not that $10 extra is lot but, I felt, I could use $120 per year savings to buy LPs).
I don't have experience with MQA, but, I have lived through many versions of digital "improvements" that never really materialized commercially except MP3. How is that for quality digital music!

Deezer.