It used to be that the word-processor was an absolutely central part of the computer software. The very first computer I owned was actually called a “word-processor” not a computer.
On subsequent computers the application I used most, by far, was the word-processor. This was common as before the Internet was popular there were many letters to be written. Any writing in a professional capacity was printed out and sent to the editor in the post or taken by hand. Asking a bank for a loan would mean writing a letter and posting it. When the computer came along a great advantage was that the word-processing files would be on the computer electronically and so could be searchable. They became records of your activities and were kept just as we keep important emails today. I still have the files for many of those letters I wrote before I used email and they are handy if I ever need to look up when such and such a thing happened.
Many people, myself included, would keep records of things in word-processing files. They would become the repository for research notes, all kinds of things.
When the Internet really happened I got into writing HTML and for this I’d use a word-processor. When I’d finished the code I’d export a plain text file and upload that to the server. In those days a personal website was probably just a few pages so it was simple enough to create them in a word-processor.
The legacy of the word-processor being, if you like, an intellectual centre on the computer most certainly lives on. When I’m dealing with people on a project of some sort the way they like to exchange notes and suchlike is to use Word documents, because that is what they are used to. Even though these files will never get printed out people still like to use them.
I think this is gradually changing, more and more people are using facilities like Google Docs.
For me the word-processor stopped being an intellectual centre a long time ago. For most of the things I used to keep in word-processing files I now use Omni Outliner. For writing bigger projects I use Scrivener, an outliner specially built for this purpose.
When I wish to create something that I want to look good on paper or PDF I export to the Pages word-processor. Pages is great for prettyfication.
So for me the word-processor has gone from being that which I used for everything to something which is for formatting “output” occasionally.