You do not have the right to a phone number without providing ID. If you're an American, those unwritten rights that come from other firm rights written down in laws and constitutions can always be argued, they're always being whittled down.

Rights for everyone are achieved through blood and toil, and if you truly want a right to anonymity and the digital tools necessary to achieve it, you will need blood and toil. Until then, we'll have to squeeze through fast developments that governments have yet to address.