This was what the Google Chromecast Audio was amazing for. £30, a fibre optic output. Then they killed it. I still have one and use it every day, and they’re fairly sought after so prices on eBay are more than twice the retail price
I wish there was some equivalent still available.
The only issue I've had with mopidy in general was getting it to work with Spotify. The API changed recently, and doesn't seem to work anymore via raspotify. I set up Tidal instead, and was good to go in ten minutes.
Also, you can send the output to snapcast and have multiple devices in separate rooms playing music synchronously.
There are various web-interfaces, or just use MPD to control the mopidy server.