LyX is good but the quality of the typesetter is not. Early on, when looking for a replacement for my TeX workflow I was taken back by the rendering. It improved lately, but still TeXmacs is a superior tecnology which renders onscreen exactly as on paper, and it is fully scriptable in scheme, including the user interface. I use it to lecture online, via Zoom, for example and I would not be able to do the same with LyX. See e.g. https://www.youtube.com/watch?v=FL50D2PpswE Also thinking about mathematics in TeXmacs is really pleasant. I wrote here my reflection on mathematical writing in TeXmacs: https://texmacs.github.io/notes/docs/art-of-math-writing.htm...

Before starting to use TeXmacs I tried LyX. It is true that the typesetting is not optimal, as often pointed out by TeXmacs users, but for me that was not a dealbreaker. I found LyX to be extremely un-customizable. TeXmacs has Scheme that allows you to do potentially anything! That made me very happy coming from Emacs land.

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.

Finding Lyx when I was at university saved me an immense amount of frustration while producing beautiful output. My girlfriend used Word 95 and I spent many more hours helping her format and fix her projects than I ever spent dealing with issues in Lyx. Once I had it setup how I needed it it just works.

TeXmacs is not a front-end for LaTeX, but a completely original system, superior to TeX and LaTeX under every point of view: typographic quality, ease of use, control over your document.

I concur. LyX makes things order of magnitude easier for a casual latex user like me.