For the same reason Facebook, Instagram etc accept AI-generated videos. All they care about is how much time you waste on their platform.

Spoiler: they want as much money as possible.

If a headline asks why, then the answer is money.

Spotify is a bad actor in many ways, use other services for music.

... because they're doing everything in their power to ensure that they can keep from paying out royalties to "real" artists?

They just launched a damn "fitness" hub. We've gone from music to podcasts to audiobooks to fitness? What's next, buying Medium or Substack?

because that's bad for the algorithmic slop pipeline that costs them way less than paying real artists