TL;DR PHP does not have concurrency so the author has taken the viewpoint of PHP becoming obsolete. Concurrency is nice and while PHP out-of-the-box does not s

TL;DR PHP does not have concurrency so the author has taken the viewpoint of PHP becoming obsolete. Concurrency is nice and while PHP out-of-the-box does not support it, I do not think it is a deal breaker (at least not for me). As long as CMS's like Wordpress are around and PHP remains easy to deploy and is installed on nearly all web servers, we are not going to see PHP becoming obsolete any-time soon.