This keeps you from ever sending the password to the site (similar to e.g. SRP).
Most sites already don't store the password. If you have a sufficiently strong password (i.e. very long, randomly generated, stored in a password manager), it is likely not computationally easier to recover the password from a hash than it is from a public-key. The only improvement here is that you don't have to trust that the site is following best-practices for storing passwords, as you never send them the password.
[edit]
It also prevents phishing attacks for those using some form of entering a password other than autofill from the password-manager.
Most sites already don't store the password. If you have a sufficiently strong password (i.e. very long, randomly generated, stored in a password manager), it is likely not computationally easier to recover the password from a hash than it is from a public-key. The only improvement here is that you don't have to trust that the site is following best-practices for storing passwords, as you never send them the password.
[edit]
It also prevents phishing attacks for those using some form of entering a password other than autofill from the password-manager.