Then why not use your 1985 Rotel poweramp instead of the Sonos?
If you added the functionality of the Sonos to the Rotel poweramp, it would have the same complexity-based problems.
Obviously I wanted the convenience of streaming an MP3 to the amp versus using a CD player.
I disagree that all solutions to this problem need the same complexity inherent in the Sonos and that the user experience could not be improved.
Keep things modular: get something like a Raspberry Pi with a USB soundcard and plug that into your good ol' amp.
Using that with shairport-sync to cast to a Woburn speaker gives me more than adequate results and I'm not even using a USB DAC nor digital audio output via HDMI, just the Pi's basic line-out.
Awesome project. Thanks for the link!
I still have a Rotel poweramp from 1985 in my front room which the Sonos is plugged into, working flawlessly. There's no chance my Sonos box will still be working past 2050.