Remove library from page based on node field value
Drupal has dedicated theme hook, hook_page_attachments_alter, for this scenario. Your theme can hook into it, check the rendered route (for your node type), and take action on the $page['#attached']['library'] render array accordingly:

function MYTHEME_page_attachments_alter(array &amp;$page) {
  $node = \Drupal::routeMatch()-&gt;getParameter('node');
  if (!is_null($node) &amp;&amp; $node-&gt;getType() == 'page') {
    //@TODO: remove the appropriate library items from $page['#attached']['library']
  }
}