I have no idea why this isn't just your email address. For everyone I want to phone, I likely have this in my "Address book" (Gmail, outlook, whatever) already.

Let me define myemail@gmail.com -> some phone number (aka phone DNS?). Kind of like how Apple does it with iOS Messaging.

If you're concerned about spam, you could in the phone (or in the provider) set up a black/whitelist (allow calls from anyone in my address book).