A perfect time for Apache Foundation to admit OpenOffice demise, and endorse LibreOffice instead. They recently were removed from Gentoo Linux, hopefully other distributions soon.
I think it's far better that the two projects merge and go the way of the GCC fork reunification [0] - one should remain standing as the brand, the other be folded into the main codebase. A few years ago I would have said that the remaining name should be OpenOffice, since it's more familiar and less awkward to pronounce for some English-speakers. On the other hand, Libre seems to be gaining some recognition of its own these past few years, so it's less clear-cut now.
- MS Office compatibility, which Libreoffice invests heavily in.
- Security: from what I remember OpenOffice struggled to ship fixes to various security issues in the past years. Meanwhile LibreOffice invest quite a bit: they're able to ship security fixes fast, and have spent time fuzzing and otherwise hardening code.
- Support: if you want commercial support, LibreOffice has that (not relevant for consumers, but important for enterprise).
OpenOffice hasn't even had a major release since 2014, only very rare point upgrades. That kind of cadence speaks for itself.