There are a variety of roadblocks associated with moving to passwordless authentication. Foremost is that people hate change. End users push back when you ask them to abandon the familiar password-based login page, while app owners resist changing them to support passwordless flows.
In this Help Net Security video, Anna Pobletts, Head of Passwordless at 1Password, talks about the benefits of passwordless authentication and what the authentication landscape will look like in the near future.