It's not because of word press. Wordpress is complete garbage that should have died ages ago. The reason it hasn't is because it still makes it easy for people to add a customizable site in a couple of minutes.

As for php, the php 5 days are long gone. Php has actually become a good a respectable language since the release of php 7, and things only continue to improve. Php is at version 8.1 and progress is not slowing down. There is even a dedicated full time dev team for php now. PHP is definitely not going anywhere any time soon and I'm more than comfortable with starting new projects using PHP. It happens all the time, especially with support from extremely good and well established frameworks like Laravel.

Honestly if you're starting a new project today, what would be a joke is to start it in node.