It is, indeed, in a very unfortunate state - that’s the best description I’ve heard.
I’d have to check navidrome, but so far I think subsonic is the way to go. There are many options for servers and apps, (none of them is particulary awesome,) but I’ve been enjoying my setup of gonic on the server, dsub on the phone and sublime music on the pc.
In the other hand, mpd for is working pretty well for room music - to me, they complement each other.
This is the way to go, IMHO.
Syncthing was weird at first, but it’s super simple, it shouldn’t take too long to get used to it.