As I mainly browse the web using #offpunk, which has no JS support, I can say that, yes, some sites require JS.
Some site that, when loaded in a full browser, display only text! Blog posts! Not even pictures or shiny effect. No, a few paragraphs of text.
And they don’t load at all without JS.
What kind of effort does it require to make sure that you straight-text-only blog doesn’t work without #javascript?
Seriously…