Try TeXmacs, it's neither TeX nor it's Emacs clone. TeXmacs is WYSIWYG scientific editing platform. Documents created can be saved in TeXmacs, Xml, Scheme, PDF or Postscript. Converters exist for TeX/LaTeX and HTML/MathML. It can also be used as a graphical front-end for other computer algebra, numerical analysis, statistics software[1]. [1] https://www.texmacs.org/tmweb/home/welcome.en.html
Another good WYSIWYG front end is LyX: www.lyx.org . I've written a few hundred physics lecture notes with it, as well as a number of Beamer presentations. I find it much easier to use than TeXmacs (mainly because of keyboard shortcuts), and the output is excellent. And yes, it produces true TeX/LaTeX.
An important thing for me was having context-aware keyboard shortcuts (that are barely possible in LyX).
Another cool thing that seems to be possible that I plan on exploring next is integrating math typing in TeXmacs with sympy and or Maxima. This would allow symbolic manipulation using the above packages directly in TeXmacs.