I disagree, having a single password is a risk even if all encryption is done locally. Why not use an M-of-N / 2-of-3 encryption scheme where the user can opti

I disagree, having a single password is a risk even if all encryption is done locally. Why not use an M-of-N / 2-of-3 encryption scheme where the user can optionally have Keybase protect one of those keys via a 2nd factor. The user would keep the 3rd in the form of a yubikey or simply written down and physically secured. This could improve both usability and security and Keybase itself still doesn't have access to your data.