Spotify is public and you can see most of their numbers -- the Cost of Revenue for 2021 was 7 billion EUR on 9.6 in revenue. The cost is said to be mostly the royalties though it would include paying the many millions to some podcasters.

The ad-supported users outnumbers premium users (236 million to 180 million) but bring in only 1/6th the revenue. So that's a factor depressing the payout per stream.

https://investors.spotify.com/financials/press-release-detai...

Let me tell you, as a musician and artist, the miniscule portion provided to the artists who supply the content is a travesty and a crime. This new partnership only serves to add more hands in the pie and squeeze out any hope of increases for the content creators. Every time you click on Spotify you are fueling the beast. I make more money selling one vinyl record at one live gig than I will make on Spotify for months. All of this is great news except for the little guys!!!

This might have changed, but generally, Spotify pays 70% of premium revenue to rights holders[1], i.e., it's a variable cost. Most won't end up in the hands of artists, but I'm not sure if any streaming or purchase platform is better for that.

1: https://techcrunch.com/2017/03/18/dictate-top-40/

For Spotify in particular, I'd rather have more money going to Google instead of Spotify. Because I don't want to be funding Joe Rogan.

I would still rather that The Google not get one cent, considering the transaction otherwise didn't need them at all, and the benefit to their involvement is rather dubious considering that all of my subscriptions may one day be inaccessible because The Google decides my account thinks wrong and closes it with no recourse.