I'm a significant shareholder in my small company and am senior and in charge of IT. I use Linux as my daily driver, nobody else in the company does. We tried for a few years to go all Libreoffice for cross-platform compatibility. I'm here to tell you that Libreoffice isn't compatible enough, and sometimes you don't have a choice but to deal with other's word docs, e.g. external lawyers, suppliers, clients etc. . I had problems internally with Libreoffice not starting properly on some windows machines, it's still a bit buggy. I KNOW Libreoffice isn't compatible enough because MS deliberately made it so, but that doesn't help me, and no, I'm not going to explain to clients etc. and other people who I want to keep friendly how wrong they are, I'm going to fit in with them because I need to stay in business.
You also need to understand that Libreoffice doesn't have the proprietary fonts MS uses (obviously deliberately), equivalent fonts exist to let docs display properly, but it's not trivial to set up for a whole organisation. Further more the underlying document model in LibreOffice and word is fundamentally different, so things like headers and stuff break all the time between the two.
LibreOffice Calc on the other hand, can completely cover excel usage, you can get away without anyone ever knowing you're using it, provided you change a few settings here and ther.