PHP today is overwhelmingly being used to augment/modify:
> Wordpress, drupal, magento, phabricator, mediawiki, sugarcrm...
Very few apps are built from scratch using PHP unless the intention is to share the application code like wordpress, drupal, etc.
On Node, you're almost always building from scratch, rather than creating plugins for an existing application.
Apples and oranges. Different use cases.