Your phone number is anonymous. In the US, you can go to a store, buy a $40 prepaid phone with cash, and use Google anonymously.
Also, Google will periodically check to see if you still operate that number and will perform spot checks on the number, asking you to verify the phone again.
1. https://www.burnerapp.com/blog/2015/3/26/burner-is-now-avail...