Slightly surprised nobody has mentioned org-mode under Emacs. It’s a slightly orthogonal use-case, not strictly editing native LaTeX. But it does a million things well, especially organizing documents of various lengths, and then exports very nice LaTeX. Not just that you could subsequently tweak, but allowing includion of arbitrary LaTeX that also gets exported.

For many use-cases it can be much more efficient to step back and let the LaTeX get written for you.