Question

Is using WordPress (or other CMS) really necessary or preferred as a freelance web developer if one has web development skills?

Answer 1

Free CMS’ cover an almost 46% of the WEB (WordPress, Joomla,Drupal)

But there are other areas like

1. JS
2. PHP
3. PHP Frameworks
4. Python
5. Java
6. and more

So the answer is, that depends on the needs of the first Job, or the market demands.