The server-client model means you can run the server (MPD, Rockbox Zig, whatever) on your homelab, and stream music to multiple clients. So you don't have to copy all your music onto your phone, you can just run an MPD client like M.A.L.P. and it will stream from the files on your server. Then there's just one copy of your music collection, tags, etc.: no more keeping tags up-to-date between the copies on your home server, your laptop, your phone... (Do make sure your files are backed up, of course).
MPD doesn't really do streaming. If you install MPD on your server and then install an MPD client on your phone, the music will play on your server when you press play on your phone. You could forward the music playback from the server to your phone, but it's not really what MPD is built for.
I like having the music player be separate from the client that controls it. I'm currently listening to music on my home desktop PC while using my work laptop, and I can control the music playback from the work laptop by just connecting to the daemon.
You can also use multiple clients if you want. Some TUI, some graphical, some utility like mpdscrobble (that just watches what you listen to and scrobbles it to Last.fm).
The interface and performance are just so well thought out and refined.
Plus it contains the earliest published code I ever wrote: https://github.com/tsirysndr/rockbox-zig/tree/master/apps/pl... , so that's fun for me.
You can also use multiple clients if you want. Some TUI, some graphical, some utility like mpdscrobble (that just watches what you listen to and scrobbles it to Last.fm).