Fingerprints do not confirm identity. A phone is not what you have in the context of this discussion. What you have would be an NFC, for example to authentica

Fingerprints do not confirm identity. A phone is not what you have in the context of this discussion. What you have would be an NFC, for example to authenticate to the phone. A phone is only what you have, when you use the phone as evidence to authenticate into a different system.