SuperuserAuthorize is here to provide full permissions to specific "SUPER" users in your app.
$config['Auth']['authorize']['Users.Superuser'] = [
//superuser field in the Users table
'superuser_field' => 'is_superuser',
];
If the current user 'superuser_field' is true, he'll get full permissions in your app.
Note if you don't have superusers, you can disable the SuperuserAuthorize in AuthComponent initialization