Really not the same thing (e.g. pandoc for html -> pdf via LaTeX) as having a webkit based renderer. They do not look the same at all; sometimes it is good to have a LaTeX output but most of the time you are going to want a more accurate representation of your HTML.
The original question didn't state that he was starting from HTML. If you want to generate an invoice or such from plain data, then LaTeX seems like a good fit. Rendering HTML is a whole different bag.
That is true. TeX is a typesetting engine, and allows you exact control over the final rendering, while HTML is a markup language, the rendering of which depends on very many factors.
