There are also 3rd party Airplay audio receiver devices. You can even make a Raspberry Pi Airplay audio receiver, if you’re so inclined.
I have an old AirPort Express that I’m only using as an Airplay receiver (I’m not using the WiFi capabilities, it’s connected to an AirPort Extreme by Ethernet), if it dies I’d probably go for one of those options. I also have a 3rd gen. Apple TV, an optical audio (m) to 3.5mm (f) adapter might also work.