Unless your site has three pages and five paragraphs of text, the likelihood that you will need to capture user input via some type of form is very high. Also, if you've been coding PHP applications you know how forms have always been a pain from the point of view of securely and efficiently rendering and processing the submitted data. As soon as you use a PHP framework such as Symfony or Laravel, you will note that an API is in place to take much of that load off your shoulders.
The same goes with Drupal 8 and its powerful Form API. Historically, it has been a great abstraction over having to output your own form elements and deal with posted values. It allows you to define your own form definition in OOP and handle validation and ...
