Playing devil's advocate: if Word 97 (or something even older like wordperfect) does all you need, why should you upgrade?
Things are different, of course, when you have to interoperate with other people (in the word processor case, mainly by reading files written by other people); not only do security fixes become more relevant, but also newer versions of the software have greater compatibility (in the word processor case, not only there was a lot of work on libreoffice towards better compatibility with Microsoft document formats, but also AFAIK newer libreoffice versions write by default using a newer version of the OpenDocument formats, so if you have an outdated word processor, you might have difficulty reading files written by other people using these newer versions).
Hi! I'm making this comment via a work computer that has Office 2010 on it. It's not the same thing, sure, but it's a great example of how people are definitely still using old office-related software.
There are people who don't need to do that. Their use case may be writing the monthly newsletter for the local rabbit breeders club, or writing that novel they've been working on for decades now (and totally are going to finish any day now! I can relate, because I've got two or three of those saved somewhere).
To these people, there are no benefits in upgrading.
(Also, I've spent a lot of time teaching my parents not to open office documents attached to emails, as that has become a popular way for people to spread malware.)
Depends; has LibreOffice gained any features since the fork? I've had to use it on and off at my previous job and the experience was pretty poor, it ran slowly, dated UI, etc.
The fork happened in 2011, 11 years ago, so there are 11 years of refinement and new features. OpenOffice is in maintenance mode so there are no new features, only bug fixes.
One of the biggest features of LibreOffice over OpenOffice is compatibility with Microsoft Office files.
OpenOffice can open Microsoft Office files but doesn't support as many features as LibreOffice does.
OpenOffice can't save in the newer Microsoft Office formats (docx, xlsx, etc) but LibreOffice can.
Also, LibreOffice now has a ribbon-like interface. To enable it, click View > User Interface and choose Tabbed.
Playing devil's advocate: if Word 97 (or something even older like wordperfect) does all you need, why should you upgrade?
Things are different, of course, when you have to interoperate with other people (in the word processor case, mainly by reading files written by other people); not only do security fixes become more relevant, but also newer versions of the software have greater compatibility (in the word processor case, not only there was a lot of work on libreoffice towards better compatibility with Microsoft document formats, but also AFAIK newer libreoffice versions write by default using a newer version of the OpenDocument formats, so if you have an outdated word processor, you might have difficulty reading files written by other people using these newer versions).