> Humans already manage secrets in the form of passwords, it's not that much different.

Humans are bad at this which is why we recommend password managers.

That said, I do think keypairs are the way forward, I just also think they need either strong integrated software support in whichever device is being used, or strong external hardware support.

(Yubikeys are nice because they kind of extend the “key” metaphor that people are already used to, but I wish they shipped with a paired backup key that was provisioned with the same key material. Maybe colored red to distinguish it.)