Apple needs to apply the Safari treatment to Apple Music and create a dedicated team that regularly releases updates detached from OS updates. This team needs to have a strong UX lead associated.
I agree with your reaction of dumb UI omissions. Spotify isn't perfect by any means, but they are doing a better job at looking at how people expect the app to work and responding to those needs with features.
For years after iTunes launched, you could be listening to Internet radio (REAL Internet radio, not Apple's BS "radio"), and there'd be artist and song metadata displayed in iTunes. But could you click on that and say "buy song from iTunes?" NO. I mean... WTF, I wanted to spend money on iTunes but Apple didn't allow that.
To my knowledge that was NEVER fixed. Incredible.