This post is part of the Test Your Skills series. You can find an introduction here. And an overview of all TYS’s currently available is over here.
There is a reason for everything!
PHP was one of the first web-specialized languages (created 1994) broadly used. Even today, 25 years later, PHP is powering at least parts of most of the web based applications on the internet (~80% - check https://w3techs.com/).