If you close your eyes, you can metaphorically hear the tides changing on the music streaming industry. The fall of Netflix is such a stark reminder of how fast these convenient services can morph into user hostile experiences.

Plus, there is the added philosophical discussion about what it means to allow a centralized corporate media conglomerate to curate your music for you. I'd imagine that their insentivisation structure over what should be heard is different than yours.

For serious though, I hypothesize that your library/playlist data (xml, maybe? somewhere? I'm just starting the journey of offloading.) is more valuable to users than the music itself. Next step is figuring out how to export Spotify's data.