"A mobile carrier's identity verification could be augmented by asking questions about who you called recently."
Except that could be socially engineered pretty easily.
Plus, if your phone dies, you're in for a major inconvenience, because no one remembers actual phone numbers any more. I remember the number I had as a kid, but nowadays, even though my mom lives in the same place, I reach her only through VoIP or cell, and both those numbers are stored on my phone, not in my head.
Except that could be socially engineered pretty easily.
Plus, if your phone dies, you're in for a major inconvenience, because no one remembers actual phone numbers any more. I remember the number I had as a kid, but nowadays, even though my mom lives in the same place, I reach her only through VoIP or cell, and both those numbers are stored on my phone, not in my head.