Looks like I’m an outlier here. I run navidrome on my server, but for jams on the go I use a HiFi Walker H2 dac/mp3 player with Rockbox. I sync my library from the server to the sd card when I add new music/podcasts/audiobooks. I wrote a python cli tool for the scripting.

At home I use the web interface on my laptop, and an old android (wifi only) phone connected to Bluetooth speakers for kitchen tunes.