How to display the views page title in a custom fieldable block
Views sets the title configured in a Views page statically in the route definition. Get this title from the current route in a preprocess hook for your specific block content UUID. Add a routecache context, so that the block changes the title when you visit different pages:

function mytheme_preprocess_block(&amp;$variables) {
  if ($variables['plugin_id'] == 'block_content:12345678-1234-5678-90ab-1234567890ab') {
    $variables['title'] = \Drupal::routeMatch()-&gt;getRouteObject()-&gt;getDefault('_title');
    $variables['#cache']['contexts'][] = 'route';
  }
}