Email accounts are the highest common denominator in online authentication. Phones are competitive, but people lose phones. Phone numbers are more common and durable, but the security of phone numbers is leagues below that of a flagship provider email account. It makes sense that so many authentication flows work this way.
When designing a "fantasy football" alternate authentication system for the Internet, start with account recovery: what happens when a user loses your fancy authenticator? If the answer is "they just don't get access anymore" or "a panel of their peers attests to them", your fantasy authentication system also needs a fantasy species of sentient beings to serve as users, because it won't work for humans.
When designing a "fantasy football" alternate authentication system for the Internet, start with account recovery: what happens when a user loses your fancy authenticator? If the answer is "they just don't get access anymore" or "a panel of their peers attests to them", your fantasy authentication system also needs a fantasy species of sentient beings to serve as users, because it won't work for humans.