Imagining pessimistic scenarios is useful if it spurs action. In this case, appropriate action would be to learn about Google's account recovery options and take advantage of them. Make sure you have multiple, independent ways of logging in. (For example, by printing out backup codes and keeping them with your important papers.)

But even this can't protect against getting locked out of your Google account due to some Google policy change, so ideally we'd rehearse how to get by without it.