Trying to help a friend retrieve her email after she lost/forgot her password, I learned how important it was to have a current cell phone number linked to the account.
She had two phone numbers linked to the account, both of which were not in use any more.
Even if you change carriers, you can have your old phone number transferred over to the new carrier. Always keep one main phone number.
Also notice that I said to use a cell phone. The reason is they will want to text you a verification code. Standard land-line phones don’t have text capability.
The moral of the story is this. When you link a phone number to an email account, make sure it’s a phone number that you are going to keep – forever! I’ve had the same phone number in two houses for the last forty years over land lines and cell phones.