Using Drupal 9 and Webform, I'm unable to find the twig template used to output /contact/form/submissions. Is there a place in the documentation that lists the twig templates? I see there is a View created that looks like it has submissions, but disabling it doesn't break the page. If there is a better way to style it, that could also work.
If you override the WebformSubmissionListBuilder, you can do almost anything you want to the results, including custom theming.