The good news is that the amount of possible software for creating larger technical documents is low. Software for creating entire newspapers like Scribus and Adobe Indesign are not suited for the task. These programs have a strength in arranging photos but they aren't supporting textual writing nor formatting of bibliographies. The remaining programs which are in theory suitable to support technical authors are LaTeX, Lyx, Libreoffice and MS-Word.
So it is some sort of contrast between LaTeX on the one hand and MS-Word on the other which represents WYSIWYG software. The open question is which one is better?
The screenshot on top of this postings shows both philosophies in direct comparison. What is shown in detail is the document structure which is later rendered into a pdf file. In both cases the user enters a hierarchical text similar to an outline tool and this is converted into linear text document.
Even if the Lyx frontend looks a bit more clean, the winner of the comparison is Libreoffice Writer. The reason is that the software can be used for many additional things than only technical writing and has the larger community. In contrast, the combination of lyx and LaTeX needs very high amount of dies space and the amount of people how are using the software has become smaller than in the past.
From a historical standpoint the LaTeX software was the dominant program for academic writing Because the program was available in the 1980s in which even MS-Word wasn't available. And even today, the ability of LaTeX to create mathematical formulas is working very well.
On the other hand, with a bit o guidance, the Libreoffice Writer software or of course MS-Word can be used very well for technical authoring. All what is needed is to activate the outline / navigator mode so that the user sees in the left pane the document structure. This allows to add new sections in addition to the existing ones.