Why is Discover Weekly and Duo Mix so useless?

[Adagio81]

Plan

Premium duo mix

Country

Denmark

Device

Android/PC

Operating System

PC: Windows 10

My Question or Issue

I bought duo mix to use with my wife about a year ago, but we quickly discovered it to be totally useless. Currently it says "This playlist is currently empty", even though both of us are listening to music on our profiles
Back when there were songs on the playlist, it was totally useless as it had no idea who listened to what. It said I liked to listen to Tagalog songs (eh, nope! That would be the wife) and that my wife liked rap and hip hop (again, the other way around). To make matters worse: After listening to it 2-3 times, my wife's songs blended into my normal playlists. For the next couple of months Tagalog songs kept showing up on my playlists

The next issue is (as mentioned) Discover Weekly. It seems to have looked at what I'm listening to and decided to find songs that does not match it. My guess is that it looks at my location and decides "Hey, you live in Denmark? Why don't I fill your playlist with tons of danish songs, even though you have NEVER listened to any danish song at all! I mean, you are from Denmark so you have to like the same songs other Danes like to listen to"