https://en.wikipedia.org/wiki/Word_processor
I think a lot of people have forgotten that “word processors” were originally mechanical devices, and then electrical and electronic devices, before ultimately becoming software.
Difference between Word Processor and text editor is in WYSIWYG mode of operation. At least for most of people.
Like my Sciter.Notes (https://notes.sciter.com) has better chances to be named as Word Processor as its primary mode is WYSIWYG. It also supports WordGrinder alike mode (Markdown editing) so users can chose what mode is more suitable for particular document type.
<graybeard> No, that's the difference between a page layout system and a word processor. </graybeard>
More seriously, word processor is to the tuple (natural language, text editor) as IDE is to the tuple (programming language, text editor). WYSIWYG is a (very, now) common feature of word processors like visual designers are a common feature of an GUI development focussed IDEs, but its not the definition of the category.
> word processor, computer program used to write and revise documents, compose the layout of the text, and preview on a computer monitor how the printed copy will appear. The last capability is known as “what you see is what you get” (WYSIWYG; pronounced wi-zē-wig).
and
> Before word processors were available, text-editing programs offered the basic editing capabilities of word processing but without WYSIWYG. WYSIWYG depends on high-resolution bit-mapped computer graphics displays.
So encyclopaedical definition of WP puts WYSIWYG as definitive characteristic of WP from TE.
"Before word processors were available, text-editing programs offered the basic editing capabilities of word processing but without WYSIWYG."
There are many, many, many of us who not only have heard of but actually once used word processors—programs or even devices that were called "word processors" as such—years before GUI, WYSIWYG word processors came on the scene.
This is the article you're referencing:
https://www.britannica.com/technology/word-processor
but the corresponding Wikipedia pages have more of the history of word processing, and an image search for "word processor" will turn up plennnnnnnty of images of things that are emphatically not WYSIWYG.