That's not what CGI is. CGI is just mode of operation where full php process being spawned on each request and then killed. It's kind a less prone to security actually because no memory or state is reused ever.
But yeah since it's inefficient I doubt it used much after 2010 when php-fpm matured and nginx got popular.
But yeah since it's inefficient I doubt it used much after 2010 when php-fpm matured and nginx got popular.