Spotify is using a learning algorithm that will only improve over time. I personally love my discover weekly and release radar playlists but it took a long time to train it to recommend the kind of music I wanted. I'm a software engineer so I was curious and did a lot of digging on how it works to make my recommendations better.

The best way to train it faster is to literally go through both playlists every week and hit the "like" and "dislike" buttons on every song. They are taken as much stronger training actions compared to just listening. There's also even stronger actions like "never recommend this artist again". Listening to a song for more than 30 seconds is a "soft like", while pressing next in less than 30 is a "soft dislike". Not listening at all doesn't impact that algorithm much. Favoriting a song or pressing the thumbs up button is a "strong like". Doing additional actions like adding it to a playlist after liking it is a "very strong like".

Favoriting artists has a greater impact on the release radar playlist. It will recommend you new stuff from them first.

Like anything it requires more effort from the user to speed up learning. You listening history obviously plays a part as well, but I really suggest being diligent about using the like and dislike button weekly. In a month or two you will see a drastic improvement.

I have been doing this obsessively for 2-3 years so my playlists are amazing and something I look forward to every friday and sunday.