Thanks, that's really surprising. Credits get into ownership and payment, and I assumed some group of authorities would have that on lock, and would have pooled all their data since it's sort of in their interest to do so. Silly me I guess!
Spotify just pays the owner of the song (typically a record label) so doesn't need to be concerned with who created it. But yeah, even then, it's surprising the Spotify credits are so poor. Everyone forgets about Ringo!
