Why does my account recovery person have to have an IPhone??

Hello ~ Apple sets these parameters:

Set up an account recovery contact*

*What does your recovery contact need?

Your contacts will need an iOS device with iOS 15 or iPadOS 15 or later, or Mac with macOS Monterey or later, and must meet the minimum requirements. Your recovery contacts won't have any access to your account, only the ability to give you a code if you need one. 

~Katana-San~