Re Amazon Music
I'm surprised that they even had anyone left in the music team.
The App went from a buggy, but usable player, where you could create playlists, listen to whole albums and was overall pretty good.
However, with every "update" it got more buggy and more unreliable then...
Earlier this year, they decided to switch to a Spotify model for the free version. People lost all the playlists, purchased music vanished, the app constantly crashed, it would just stop playing, if you got it working in the first place and was generally unusable.
If you think this is over exaggeration, on Android it went from about 4.6* to 2.7*. Given how many reviews there were in place before, it takes a huge amount of bad reviews to force it down that much.