FWIW, I used but never liked LaTeX and only because I needed a good way to deal with expressing mathematics.
However, using org-mode and exporting to LaTeX is a winning combo for me. With org-mode, I can focus on writing and not typesetting.
Yeah there are plenty of relatively easy to use lightweight markup languages which can generate LaTeX[0]. If you don't need the specific properties of LaTeX but want the option of LaTeX-typeset output, use something else and compile to PDF through LaTeX.
[0] because Pandoc generates LaTeX even if the reference implementation doesn't.