They also commission music from "ghost artists" that they can pay a fix rate, then place said artists in popular playlists to reduce royalty payouts.
1. Spotify made a playlist that's "Chill Jazz To Study To" that's really popular.
2. They realize that listeners don't actually care about the specific artists in the playlist since it's background noise.
3. There are companies who specialize in making "b-roll" music for background noise and have a huge library of it just sitting around.
4. Spotify realizes they can license them on the cheap.
5. Profit?
Seems like a win for everyone involved including the listener who gets fresh tracks in their study playlists basically forever.
If you're the kind of person who would manually queue up 100% of your songs for the day then Spotify Generic songs aren't an issue. If you just hit a "2020s R&B" playlist and go that's where it feels more sketchy.
The other big difference is that TV and movie productions have always been "assemble when needed." Production companies are typically very thin business shells who hire in 99% of what they need per show. As opposed to a band or artist like Taylor Swift or The Rolling Stones, where the core persistent business unit is the talent itself.
The only reason is because unions in the movie business negotiated this. That's it.
There are no unions of note in the music business, and artists get shafted left and right.
( If you need a baby break try @ 1:20 in https://www.youtube.com/watch?v=Z7DAGXVC1tQ )