Hello notheapp,
Thank you for reaching out in Apple Support Communities. We understand you'd like to confirm if an email address is a requirement for an Apple ID. We can help provide you additional information.
For users that are in China mainland, it says: "In China mainland, you might be required to provide a +86 phone number for your Apple ID. You can change the number later, or change your country or region to a location that doesn't require it. This number is only used for verification purposes." That information is outlined here: How to create a new Apple ID
Now if you do not reside in China mainland, an email address is needed as the Apple ID account to access Apple services like the App Store, Apple Music, iCloud, iMessage, FaceTime, and more. Here's more information: Where can I use my Apple ID?
Kind regards.