1. How much is compatibility with outside users and past documents necessary? No office application can successfully, reliably convert anything but relatively simple documents (have LLMs done better somehow?). Each conversion reduces fidelity and often integrity; send a few revisions back and forth and it can become a problem. Simply adding a small headache every time an outsider emails your users' a document - or vice verssa - becomes a big issue. Regarding past documents, some users create complex applications in Excel, for example. How much of a problem is that for these users? How will those problems be solved?
2. What is the system management story? Essential to IT beyond even 30 users is a way to deploy, administer (including configuring settings), and upgrade/patch applications en masse. Microsoft provides those tools and Office, of course, integrates well with them. There are third party tools, but they need to do much better than exist; they need to function efficiently and reliably - imagine the deployment bug implemented en masse. Are there such tools for Linux and LibreOffice?