The trouble is hardware. I use rpi 0's to 3's with snapclient installed, and an audio hat, either a quality DAC or an Amp. This then feeds your amp or speaker.
I run snapserver on my computer in the common area, and it has Spotify, as well as any other audio source (YouTube, mp3's, streaming radio, etc).
I like it, I even built a portable speaker that takes a ryobi power tool 18v battery
There is a delay between the server and the sound, but all clients are synced.
It is a bit of a process, but the software is on github.
Yep, no movies, though I think vlc can change the audio offset to suit.
I use Spotify to all interact with what is paying. And the app to adjust different volumes. And you can have multiple streams that you direct in the app.
There is also home assistant component which we used primarily