In the end I use it so sparingly (social gatherings) owners of detached homes without shared walls, could save the money and time and just turn up the volume.
That said, as always, YMMV
I love my tech stuff, and I've got home assistant doing the lights, but it never once crossed my mind to mess with the sound system, except for occasional hifi upgrades. Eg next up: run a subwoofer cable from the stereo amp to the kitchen, but I'm in no rush.
I have the same experience - my home runs seven Logitech (formerly Slim Devices) “squeezebox” players from a home server with a ripped collection and options for Spotify. The networked players either have their own speaker, or are connected to amp/speakers. In practice almost all of our music plays through these devices. It’s great.
The only time we connect multiple players to sync up is at larger parties, like once a year. It’s just one button press to do it, so not using this capability isn’t that it’s too complex, it just turns out not to be that useful to us.
The main use case for multi zone audio is handled by the A/B/A+B speaker setting on one particular amp.
As you say, YMMV.