The problem is logging into your Google account without your 2FA device or phone number.
The answer in all these cases is having more than one option enabled. I just recently tested my Google and Apple login simulating a loss of phone and computer. It was tough but there are options (e.g. Apple lets a friend be your full 2FA, so you can even recover encrypted data)
I always back up the codes for the Google Auth stuff. They are just strings like VN3WBOTLQZUDFIWG You can put them in a doc / email them to yourself / whatever.
The answer in all these cases is having more than one option enabled. I just recently tested my Google and Apple login simulating a loss of phone and computer. It was tough but there are options (e.g. Apple lets a friend be your full 2FA, so you can even recover encrypted data)