I still have several static php and html sites, however, having a database behind your content and responsible for serving your content is a must I feel in this day and age. Hence, a CMS such as wordpress is great to get sites up and running quickly, so you can concentrate on your content.
My site casinos-online.co.uk is a php flat file site, apart from the news content, which is stored in a mysql database. This was a must, as the news gets regularly updated throughout the day and also by having it stored in a DB allowed me to configure it, so as and when we receive the articles, they are automatically uploaded onto the site. Meaning, I do not have to spend hours every day, having to manually add the news articles.