They don't.

Apple, Google, and Amazon can afford to lose money all day long on the music streaming services that they each offer. This is because the services bolster their broader ecosystem of services and products whose aggregate value is far greater than any individual piece on it's own.

That's why Spotify is in a precarious position because streaming is it's only bread and butter.

Similar to UberEats + Uber versus a standalone service like DoorDash or Postmates. Uber doesn't need to make money on UberEats in order to be a successful business. Postmates does and that's a huge problem because delivery is a brutal business.

Exactly, the only realistic option Spotify has is to be bought by one of the big 3 (an exit), not an IPO.

Music was never intended to be a revenue generator for their competitors.