I understand that Google already has my phone number. That’s not so much of a problem for me. I am trying to limit the amount of personal information that I hand out to websites & services. I believe that companies shouldn’t need my personal phone number to create, maintain or secure my account. If I need security, I’ll install 2FA TOTP. If not, that’s still my decision and I shouldn’t be forced. Especially not in form of having to provide my phone number.