HTML/CSS are slow. The true way is ".txt"
Edit: I mean this as a sort of lazy way of making a reductio. I don't think .txt is better than HTML/CSS for pages (and I hope that's obvious). I also don't think having no JS is a good idea.
I believe in progressive enhancement, and to a first approximation, I think that all websites have at least one feature that they could implement in JS that would be "a good thing".