Google 2FA app does not backup your 2FA. If you lose your phone or get a new phone this data is lost and then there is no way to log into the exchanges where you have 2FA enabled. It can take months to get your account back that way because support is very busy with new accounts and overloaded.
If you have not backed up your 2FA key, the do the following:
- Go to exchange and login
- Disable your 2FA
- Create new 2FA and write down your backup key in a piece of paper
- Store the piece of paper somewhere safe(i have 2 copies just in case in different places)
Now when something happens to your phone or you lose it then you can just send the support this backup key and that process will be alot faster to get your account back.