Why in User doctype , Phone has not option set as "Phone"?

I am replicating my question raised here: Why in User doctype , Phone has not option set as "Phone" ? · Issue #6713 · frappe/frappe · GitHub

I was given a task of formatting Phone in an international format system.
Searching about it, there is validation in “Data field” if option Phone is set

But as I see in core doctype like User frappe/user.json at develop · frappe/frappe · GitHub
this option is not set.

If where any reason that I am missing ?

Upgrading and adding more sophisticated Phone parsing libs like GitHub - google/libphonenumber: Google's common Java, C++ and JavaScript library for parsing, formatting, and validating international phone numbers. or libphonenumber-js - npm can be valid solution to upgrade this parsing ?