The SubSonic API has long been the quasi standard for (mobile) media streaming.* I’ve used e.g. DSub (FOSS Android app) for both Navidrome and Airsonic, and maybe one or two more, on and off for many years.
Having one Subsonic compatible app would provide access to many media servers.
I just tried to connect Sailfin to my Navidrome, it did not work (it did work for Jellyfin). Apparently Jellyfin is not SubSonic API compatible.
I don’t like Jellyfin’s PHP dependency very much. Navidrome works much better for me.
BTW - because I know somebody will bring it up - while the browser works well enough, it won’t allow me to switch off the screen and still continue listening.
* This is even official nowadays.