I have up until the last few days had no issues with your wonderful service. But in the last day or so i had an error causing my phone to have to be wiped. This caused my backup files to become unreadable. In this mess i have lost my two factor backup and there for my Mozilla account.
This is where I find your service lacking behind Google and Microsoft. I have a Microsoft and google account for various items and did not have this issue. They provided me with alternative options to confirm my ID and recover and reset my account options.
I feel that this is a major issue that should be addressed and an Org. As large as should have been able to foresee and fix or resolve.
Thank you for your time.
P.S. I will continue to use and recommend your service just without the two factor ath. I feel that you generally have a privacy focused user friendly service and it just needs a few touch ups.