You don't need more than what you have. You have essentially built a minimal MVC. Everything else you add is just stuff that other people added to other MVC projects to make life easier for them in some way. Web MVCs are basically just opinions on the way to handle HTTP requests and are meant to speed up the dev process if you agree with all of its boilerplating/tooling.

My only recommendation is to just keep yourself aware of url/form encodings, path handling, and common pitfalls related to handling HTTP requests in general.