Earlier quoted context omitted.
Apple’s implementation uses SMS as a backup. Thinking is probably that if you only have one device, it’s usually your phone; so you would have been able get your 2FA code via text. It’s not easily discoverable though, so easy for you to miss it.
So if I have a single device, a phone, and it gets stolen... what is the path to get my data back? And in the interum, if the theif swaps my SIM into another phone they now have my 2FA via SMS? This all seems very messy when bad things happen.
I think you still need to know your password, but that’s pretty reasonable.
They also added a similar feature to allow you to get into a loved one’s account/phone after their death if they set it up.