- I don't use mobile internet on my phone, so having the music files at hand is quite natural. Wouldn't be able to listen to the music on the go otherwise
- Recommendation algorithms of streaming services like Spotify weren't good enough for me, so I couldn't simply start the player and do my thang without skipping the tracks I don't like
- Streaming services often don't have many obscure tracks
Ended up realizing that, for me, using streaming services as a daily-driver is mostly like fighting windmills. But I still use them as a discovery tool.
Now, the issue with local files was, I had to manually syncronize any modifications among devices. So I installed Syncthing [0] to sync my audio folder between myphone, PC and NAS. Syncthing can do online syncs via their relay servers, but I set the clients to only listen on local addresses, and disabled all the over-the-internet stuff. I'm quite happy with this setup.