Oh, please! No! No! No! India bulldozed a national identification number (called Aadhaar) on its residents and it has made more people vulnerable to many kinds of attacks, including phone number hijacking, draining people’s bank accounts, etc. To say that it’s been an unmitigated disaster would be an understatement. As with things related to government, the governing organization for Aadhaar, called UIDAI, always claims that it’s completely secure, while ignoring the fact that linking one number to everything in one’s life increases the attack surface and the severity of the threats.
So please research on the number of ways Aadhaar has failed, and is making some feeble attempts to recover, before getting into a “let’s create a new static number to identify people with instead of a phone number or SSN”. That’d just be changing the narrative without achieving anything.
Bottom line, it’s not the phone number that’s the problem, but having a unique and non-changing number and linking it to everything else (including one’s phone numbers).