I think it is important to note that the term CMS does not need to mean a 3rd party "black box" software package.
I built my site from scratch 10 years ago and built in my own CMS feature. It is, for all intents and purposes, a custom CMS site. Completely flexible.
If I want to serve static content, I can have all my pages generated into static pages. If I want more speed than that, I can have all my pages served straight from memory (RAM). I can do anything since my site/data is stored in a database backend.
Ahhh, nevermind. Use what every you like and whatever you are comfortable with. To each his (or her) own.