Its backed on an RPI-4 NAS I built, running the plex arm linux code. I have another RPI-3 in the living room as a headless music source to an amp. In the past I've used HDMI to VGA+audio splitters to scatter output to devices. This is my music, on my disks, under my control. I own these rips, the bits are mine. I keep the discs behind them on the shelves just in case but I haven't opened a CD case in nearly a decade.
Plex isn't perfect, but its pretty good. plexamp is available when you take subscription, and periodically plex offer lifetime buy deals, which I leapt on.
Jellyfin is [edit: not - it's from emby] another variant of the same codebase (forked)
I also paid for tidal. I don't like these music rental schemes, I like to own my CDs and rip but for exploration, finding what you don't know, its really useful and unlike some of the other choices, its owned by musos. I think at some level its still greenwashing the truly awful world of A&R/IPR on music, but if anyone has to get payola here, it might as well be musicians.