You can implement meta boxes on other non-post_type admin pages but you need to manually call [`do_meta_boxes()`][1] where you want them to output.  You also need to make sure that [`add_meta_box()`][2] action is run prior.

You can see an example of this in **/wp-admin/edit-form-comment.php**...

    do_action( 'add_meta_boxes', 'comment', $comment );
    do_action( 'add_meta_boxes_comment', $comment );
    do_meta_boxes( null, 'normal', $comment );

They ran two [`do_actions()`][3] but you can just use one if needed and it can be something custom like `do_action( 'add_meta_boxes_banner', $someArgumentIfNeeded )`.  Basically, with your current code the [`add_meta_box`][4] action is never being triggered because the custom page doesn't run a `do_action()` for it.

For the JS sortability and expand/collapse you will also want to make sure to enqueue post.js.  You will need post.js and postbox.js (the later of which will come along with post.js) which you can enqueue like this...

    wp_enqueue_script( 'post' );

And wrap your output somewhere with the class `metabox-holder` on a parent `div` to fix some broken styles...

  [1]: https://developer.wordpress.org/reference/functions/do_meta_boxes/
  [2]: https://developer.wordpress.org/reference/functions/add_meta_box/
  [3]: https://developer.wordpress.org/reference/functions/do_action/
  [4]: https://developer.wordpress.org/reference/hooks/add_meta_boxes/