Currently I can just message them the password or even write it down on a post-it note and they'll have everything they need to complete the task as me. How does it work with passkeys? Does the spec allow my passkey HSM to securely share the secret by encrypting it against the recipient's passkey HSM? Can it use the concept of leaf certificates to sign a short-lived certificate allowing access to that credential without sharing the credential's secret itself?
I can't advocate for passkeys until the concerns above are resolved. The push for passkeys seems like yet another attempt to remove control from the user.