How to print token in webform-confirmation.html.twig?
First, talking about your twig extension:

{{ webform_token(....) }}
{{ drupal_token(....) }}

I've never seen drupal_token twig ext so let it out of here. or you guys can comment to help me update this answer.
For webform_token function, the real back end function of it you can check from this file: webform/src/Twig/WebformTwigExtension.php line 102. (v5.23.0). And it said that
public function webformToken($token, EntityInterface $entity = NULL....) {
  // Allow the webform_token function to be tested during validation without
  // a valid entity.
  if (!$entity) {
    return $token;
  }
  ...bla...bla
}

Mean that, if your code not given entity, it will return a string that you inputed. and the result will be like what you did.

Back to your case
If you look into webform/templates/webform-confirmation.html.twig template file, you can see the Available variables:

progress: Progress bar.
message: Confirmation message.
back_url: URL to the previous webform submission.

And the others Available variables can found at template_preprocess_webform_confirmation() of this file: webform/includes/webform.theme.template.inc. And they are

webform,
webform_submission,
source_entity.

So, it mean that you can use {{ webform_submission.data.field_name }} in webform-confirmation.html.twig template file; instead of using token like the way you did above.
*Note: Try to avoid using twig extension in twig template would make you easier in debugging and maintenance.