If I were offering a free (as in price) alternative to MS Office, I'd first recommend WPS Office over LibreOffice, even though it's closed-source. It has a much better interface out of the box. But I'd use something to block it from phoning home to its probably Chinese government-beholden servers, like OpenSnitch for Linux* or LuLu for macOS.
(*) https://github.com/gustavo-iniguez-goya/opensnitch