Self-supplied metadata in music catalogs is notoriously shit. The degree to which most rights owners don't give a damn is telling.

Spotify's own metadata is not particularly sophisticated. "Valence", "Energy", "Danceability", etc. You can see from a mile away that these are assigned names to PCA axes which actually correspond pretty poorly to musical concepts, because whatever they analyzed isn't nicely linearly separable.

Especially since they scraped Spotify's popularity rating as well