No. It is a biometric identifier. That is what it is. A username is a human language convenient symbolic pointer that is meant to be public and used socially. I am still confused about why this particular incorrect meme is so persistent. "Something you know, something you have, something you are" all are simply different classes of authentication factor, and all are distinct from names, or UIDs, or any other bit of meta-information that isn't for authentication.
Just like "something you know" can have different strengths, "something you are" can too and changes in technology and threats will enable new options alongside new attacks as we go along. It's a process.
Just like "something you know" can have different strengths, "something you are" can too and changes in technology and threats will enable new options alongside new attacks as we go along. It's a process.