Now, to be fair, first-party MS Office also has this problem. The online versions can't handle absolutely everything that the desktop applications generate (although they do better than Libreoffice), and even compatibility between, say, Office 95 and modern MS Office is not 100%. I believe MS Office is architecturally incapable of complete compatibility, since its file format is basically a binary dump tied to the current version.

One of the many reasons why my particular industry has standardized on TeX/LaTeX/PDF is because it gets along much better with other humans in terms of file format compatibility over the time scale of decades.