For PowerPoint and Excel, I strongly disagree. People do horrific things with Excel that I think are far beyond its intended usage, but they love it for that. You can't pry Excel away from people in finance and a lot of quantitative/non-programmer roles.

Word is more debatable. Yes, if you use it just for taking notes or something, the alternatives are fine.

But if you want to make a nice-looking document, Word is still just a lot better. I've never seen a fantastic Google Doc, for example, even that my company's designers have worked on.

And LibreOffice is another, older generation of UI/UX that is far behind Office at this point.