It's very small scale but I have converted at least 10 Apple Music users to full time Spotify users. I talk to a lot of my users and every once in while they'll tell me that they ended up switching platforms because of The Jukebox App.
I don't say this for bragging rights, I say it because I think the jukebox functionality is something Spotify should lean into if it wants to capture even more of the streaming music market share... Maybe they will!?