[wccrawford]

I just went through this situation with a couple non-Google companies when I upgraded my phone, not realizing that their authentication info wouldn't transfer when Google transferred my data to the new phone. I thought I had double-checked that I had everything, but this got missed.

It was a pain for all of them, but it was worst for the ones that I had no other auth systems set up. (Or the ones that had my old phone number for SMS still, even though I thought I'd changed it everywhere.)

In the end, there's still no good system for real security. You're either stuck with a device you might lose (or someone might steal), or stuck with an account that you might cancel (or someone might steal). Or use biometrics which are just not ready for prime time.