I spent over an hour going down a rat hole on this. I had worked on a Logic audio session (which was at 48K) with some headphones on and then went over to my iOS simulator to work on my audio code for my app and started getting this crash. Unplugged my headphones, still crashed. Rebooted simulator, deleted app from the simulator, restarted XCode and machine, still crashed. Finally I went to system preference on my mac, selected: Sound & Input, plugged in my headphones so it says "External Microphone", also went to the simulator I/O settings for audio input set to "Internal Microphone", and then my app was able to startup in the simulator without crashing while trying to create an AKMicrophone()...

You can also try this for getting the iPhone 8 Plus installed: When you create the simulator, if you tap on "OS Version" there is a drop down for "Download simulator runtimes", (which takes you to the "Platforms" settings screen, there is a little "+" icon there select "iOS" and from there you can install iOS 14.3 (which is 5GB) or another iOS version if you like, so your iPhone 8 Plus can run on that instead. The don't make all of these buried drop-down screens with the little "+" icons easy to discover...