If you've already got it, I'm not exactly sure what you think the toil is? You just copy it places. Maybe just the MP3s for things like phones. Then use an MP3 player.

If you mean the inaccuracies of the metadata, again, you just peck at it as it bothers you. You don't have to fix it all at once. Any decent MP3 player can do searches for specific songs. Nor do you have to do a hard cut from streaming services.

I do have it all hooked up on Syncthing so my changes stay in sync but that's not exactly a hard thing. It's only marginally harder than a straight copy, and sometimes honestly even a bit easier given how dodgy phones can be about large normal copies.