As an untrained but interested bystander/hobbyist, the scores engraved by Lilypond are orders of magnitude better than those produced by the mainstream WYSIWYG editors, in the same "I deeply care about typography" sort of way that you get from documents produced with TeX but not Word or Google Docs. My ex-wife is a musician and a music teacher, and (especially for her teaching job) ends up writing a fair bit of sheet…
My wife is also a musician and music teacher, but I have not been able to persuade her to tackle Lilypond. (I have occasionally done projects in Lilypond for her, and the results are great, but the barrier to entry is too high for her to scale.) What she has found much more approachable is MuseScore ( https://musescore.org/ ). I haven't done a careful comparison of the output to see which scores better [sorry!], but…
The focus of musescore has changed over the past year or two, all triggered by a funny youtube sh*tpost criticizing its UI (it was one series of such videos taking shots at all the big notation programs).
https://www.youtube.com/watch?v=4hZxo96x48A
The guy who created it is a trifecta: a composer, a typographer, and UI expert. The team at musescore took the criticism in good humor, and hired the creator of the video (Tantacrul, aka Martin Keary) to help them change it. The first phase was getting rid of some low-hanging fruit in the UI department. That work is ongoing.
The main focus of the next phase (musescore 4.0) is the quality of the layout. Some of those improvements already landed in musescore 3.6.