For my use case this is less secure because I keep my computers clean of malware, and my hard drives encrypted. I don't reuse passwords and I don't log into my

For my use case this is less secure because I keep my computers clean of malware, and my hard drives encrypted. I don't reuse passwords and I don't log into my account from devices I don't own. My phone, on the other hand is easy to steal. Anyone who has my sim card can use it to log in. I've also heard it's trivial to use social engineering to redirect a phone number with some carriers. Also, I often don't have signal in buildings, so that makes this option useless. For other people the SMS option might be better. They let you choose which one you want to use. I guess we'll hear about the results of this experiment later on.