Password manager still have weaknesses. For one, you are still sending the private key to the server. This may happen in plaintext, or the password may not be e

Password manager still have weaknesses. For one, you are still sending the private key to the server. This may happen in plaintext, or the password may not be encrypted/protected properly server-side. And it requires you to keep a database of passwords that you need to synchronize between all of your devices. Using something like public key authentication allows you to use the same public key for every website. Your password management software and synchronization strategies are both suddenly a lot simpler. Server-side mistakes are less problematic to the end user. It removes several points of failure, and has greater flexibility against user, server, and developer mistakes.