In 2017, Airplay 2 wasn’t yet A Thing and multi-send hadn’t been added yet to iOS. However, I still wanted to be able to have synced audio nodes around my condo (I was spoiled from my time working in pro audio). I had a spare Android tablet that I installed AllStream onto, an Airport Express from eBay, and Pi Zeroes that I added DACs to output to desktop speakers around our (then) new condo. Et voila! (Excuse the mess, we had just moved in!)
Nowadays the Pi0s have been mostly retired, but since Apple added Airplay 2 to the Airport Express firmware before discontinuing them they’re still going strong in our house and I’ve even bought a few more since they make great cheap Airplay 2 receivers and output either line level or optical digital.