Subsonic seems—for all intents and purposes—dead. There is an active fork called
https://airsonic.github.io/ and I believe they have been working on Sonos. Airsonic is completely open source, unlike Subsonic, so it doesn't require a key.
Personally, I had been looking for an excuse to drop *sonic because of its reliance on Java and tendency to have its DB corrupted. I tried out Navidrome but it was too basic for my needs.
I finally settled on Emby, in large part because it supports the "composer" ID3 tag and is under active development. Also, I had already been using it for video streaming, and while it definitely is a better for video, they are slowly making refinements to make it a better audio streamer, so maybe check it out.