The HTTPServer object is very close to the HTTP protocol. While this is powerful in the same way that driving a stick shift car gives you low-level control over a car, typical web application programming is better done at a higher level. It's better to abstract away the HTTP details and concentrate on your application.
The Node.js developer community has developed quite a few modules to help with different aspects of abstracting away HTTP protocol details. You can take a look at a couple of curated lists at http://nodeframework.com/ and https://github.com/vndmtrx/awesome-nodejs.
One reason to use a web framework is that they often provide all the usual best practices that have come from web application development of over 20 years. They have been listed as follows:
Providing a page for bad URLs (the 404 page)
Screening URLs and forms for any injected scripting attacks
Supporting the use of cookies to maintain sessions
Logging requests for both usage tracking and debugging...