If you read the parent comment here as I did originally, about it being text as opposed to a number field, see points 18, 19, 23, and 25 on https://github.com/google/libphonenumber/blob/master/FALSEHO...

The field on the form is indeed of `type=tel`, which Mozilla helpfully points out has no validation (see the above document): https://developer.mozilla.org/en-US/docs/Web/HTML/Element/in...