It is, but so are MS Office and Google Docs. What's really bad about LibreOffice is that it's a monolithic application, so if I only want LibreOffice Calc, I also need to have LibreOffice Writer, LibreOffice Impress and all other nonsense which I don't need.

But yea I don't use it anyways, I convert Markdown to PDF with pandoc for writing documents, or just use LaTeX in some rare cases, same with presentations, and I use sc-im for spreadsheets.