. . the print formatter for a markup word processor does exactly the same, interpreting the markup language to fit the end user's (or printer's) requirements.

And no do NOT misinterpret what html is for. Note that none of the pages I do stop the browser from doing all the adjusting that's appropriate - within the constraints of making a comprehensible page. Your resolution is 32,000 x 64,000 - my paragraphs will fill your screen edge to edge. You want a BIG type size - that'll work too.

You will never find one of those empty right margins in my work.

On the other hand, having worked with other markup languages, I find html a real struggle to make sure the browser can interpret the page in a comprehensible manner. A bit more attention to layout and whitespace would have done wonders.