Right now the word processor choices are Word or open-source Word clone, so I don't see the point for the end user. I use Libre/NeoOffice, but it's no easier to use than Word. I'd like to see a word processor more like old ClarisWorks/AppleWorks.
Or you could just use LaTeX with the text editor of your choice. Yes, you can write letters in LaTeX, yes, that is easy and yes, it takes me roughly one minute to get a perfectly-formatted simple letter, which is roughly equivalent to the time it took Word to start the last time I tried it (~2008?)
If you're going to work in LaTex you might want to use Lyx.
Otherwise, working in a LaTex compiler is full of problems. Texshop is forgiving, but where is the Zoom view feature? Other compilers simply halt without letting you know why.
As a word processor, Lyx is not bad at all.
Exporting from Word to LaTex is not easy.
If you’re new to LaTeX, I presume that Lyx might be a good start, but personally I prefer AUCTex with standard Emacs – the zoom feature being in my PDF viewer (evince-gtk for simplicity).
Wordperfect?
Depends on what you're trying to do.
Writeroom/Darkroom and clones.
Pages.
Scrivener.
Final Draft.
Celtx.
Write (myownapp)
etc.
(no affiliation with any of these)