I have a Rocku streaming stick and it won’t work without an internet connection

Notably absent from your setup is Linux. Did you try that for your server?

Welcome

Depends what you want to play it on. In my house we have:

3 laptops 2 tablets 2 mobile phones (1 android, 1 iPhone) TV

Not all these devices support local storage for music and it’s a pain to sync files between them. With Jellyfin the complete library is in one location with a consistent interface. It can also be made available remotely if I choose.