While technically correct, a private key will usually need to be encrypted to provide adequate security.
From the user point of view, they will still need to remember the password to unlock this private key.
From the user point of view, they will still need to remember the password to unlock this private key.
Likely you will envision a system to register your key. And then you have to have a bootstrap to authenticate to this system. Probably a password.
List of problems with every approach always falls back to, "what happens if you lose it?"
And the resolution to that is always outside of the technical chain.