Aside from what other commenters told you: LaTeX just typesets better, meaning that it will choose line-breaks, inter-character and inter-word spacing, ligatures, hyphenation, etc. much better than your regular browser.
Try justifying text on a relatively narrow column in HTML, and then try it with LaTeX. There's a world of difference in readability between them.
Try justifying text on a relatively narrow column in HTML, and then try it with LaTeX. There's a world of difference in readability between them.