Another advantage of LaTeX over WYSIWIG alternatives is its simple plaintext representation. If we can still open any documents from our time period in 200 years, we'll be able to open that old LaTeX document of yours, because it's just ASCII (or Unicode in the case of XeLaTeX). And given the portability and simple requirements of the open source, exceptionally well documented TeX code base, it isn't far fetched to imagine someone could even run your documents through the actual LaTeX typesetter, if they really wanted to, 200 years or so from today.

Do you think anyone will still be able to open your documents in Adobe InDesign 200 years from now? This may not matter to everyone, but if it matters for your purposes, LaTeX has a clear advantage here.

EDIT: I'm not affiliated with the author of this article.