If that works for you, great. But I for one like to listen to music when I'm out and about and don't have access to an NFS mount.
In the house: NFS read-only for desktops and laptops; Owntone to send music to Wiim Mini or stereo receivers (Yamaha, Denon, Marantz, Onkyo -- all of them are compatible).
Outside the house, JellyAmp on phones.
2. What if I want more music than is easily carried on an SD card? I have literal TBs of music.