RouteSubscriber.php

<?php

namespace Drupal\node\Routing;

use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;

/**
 * Listens to the dynamic route events.
 */
class RouteSubscriber extends RouteSubscriberBase {
    
    /**
     * {@inheritdoc}
     */
    protected function alterRoutes(RouteCollection $collection) {
        // As nodes are the primary type of content, the node listing should be
        // easily available. In order to do that, override admin/content to show
        // a node listing instead of the path's child links.
        $route = $collection->get('system.admin_content');
        if ($route) {
            $route->setDefaults([
                '_title' => 'Content',
                '_entity_list' => 'node',
            ]);
            $route->setRequirements([
                '_permission' => 'access content overview',
            ]);
        }
    }

}