It is stupid but today that makes sense in places where SIM card requires registration by full first and last name - which is majority of the world. You have to register SIM otherwise phone will be working with emergency services only. And that gives the possibility of identifying you by your phone number on whatever service, platform that asks you to provide phone number for security reasons.

I really don't want to spread gloom here but last 15 years felt like stripping down anonymity by both law and social engineering. And now we're facing even more direct online verification under the classic pretense of "think of the children". The Wild West period of the Internet is over and what soon will arrive should concern us all.