The internet itself supports many different modes of communication with many different identifiers. Different modes of communication serve different needs.
I have many email addresses and a few phone numbers. Using an email address instead of a phone number would add friction for people typing my "phone number" into their phone, and using a phone number instead of an email address would be a loss of clarity for no gain. I see unifying the two identifiers as being the inelegant thing.
The question is: what would be the benefit of restricting the utility of phone service in the way you propose? It looks to me like there's nothing to be gained by doing that.
I have many email addresses and a few phone numbers. Using an email address instead of a phone number would add friction for people typing my "phone number" into their phone, and using a phone number instead of an email address would be a loss of clarity for no gain. I see unifying the two identifiers as being the inelegant thing.
The question is: what would be the benefit of restricting the utility of phone service in the way you propose? It looks to me like there's nothing to be gained by doing that.