Recently I stumbled upon the following use case:

On my single-authors.php page (the detail page for an author), I wanted to showcase all the posts written by that author. (Note I created a custom post for author rather than using WordPress users since none of the authors log in to WordPress.)

To achieve this, I added the following to my functions.php:

add_action( 'template_redirect', function() {
    if ( is_singular( 'authors' ) ) {
        global $wp_query;
        $page = ( int ) $wp_query->get( 'page' );
        if ( $page > 1 ) {
            // convert 'page' to 'paged'
            $query->set( 'page', 1 );
            $query->set( 'paged', $page );
        }
        // prevent redirect
        remove_action( 'template_redirect', 'redirect_canonical' );
    }
}, 0 ); // on priority 0 to remove 'redirect_canonical' added with priority 10