For my own (extensive) DTP work, I use LaTeX which is not WYSIWYG, but has advantages in my situation over some other DTPs from Word to Quark and InDesign. (Note: LaTeX's underlying TeX engine has been running on IBM and other personal computers since 1984. Also note, the perception of many people that TeX was only for people doing math work is shortsighted; yes, Knuth created TeX to typeset books with a lot of math, but TeX was also better than many other systems in terms of its general typesetting generally.)
I starting using LaTeX more than 20 years ago because it has a non-proprietary, visible, well documented, and basically unchanging markup language; thus, I would never again have to worry about getting "incompatible file type" messages or deal with format converters in the face of new software releases. Also, TeX is free, unlike Quark and InDesign. (By the way, I never write math or science; I suppose my use of LaTeX is like that of many people from the humanities who use TeX and its derivatives.)
Over time I have come to appreciate other aspects of LaTeX that make it superior for me to other DTP systems. (1) With LaTeX I can specify layout more precisely than with WYSIWYG systems. (2) Because LaTeX editing is done in an editor separate from LaTeX, I can use a powerful and work-saving text editing system (e.g., Emacs) rather than being limited to the capabilities of a WYSIWYG editor. (3) I can write programs in other text processing systems that generate LaTeX markup for printing, e.g., from data taken out of databases or to repeatedly generate certain sequences of typesetting commands. (4) In my experience, LaTeX is definitely the most productive when an overall document consists of many text and image files, inter-file cross-references, references and notes, etc. (5) There is an exceptionally helpful and knowledgable worldwide on-line user community for LaTeX and the other TeX derivatives. And, being effectively open source, there is a constant stream of new LaTeX capabilities coming out of the user community (without fundamental change in the user interview).