Office suites, as the name suggests, are for office workers. You know, the kind of people who write stern letters on official letterhead, work on Excel workbooks, and give PowerPoint presentations in front of other people.
It's probably not the kind of job that a typical programmer would like to have, but there are hundreds of millions of these jobs in governments, schools, and corporate offices all over the world. I bet they make up a much larger market than all the programmers in the world combined. We need to get out of the programmer bubble in order to see why a seemingly obsolete piece of software like LibreOffice is still such a big deal. Just one country deciding on it as the official standard means millions of people will be using FOSS in a critical part of their workflow.
I did my M.A. and Ph.D. in the humanities and wrote both dissertations using Microsoft Word. My professors would have been very confused if I had sent them anything other than .doc(x) for review.