That is so not true. The golden rule of "say what you mean" is about the writer. It gets broken constantly by LLMs: they always add words that do not reinforce the meaning, but dilute it.
lmao. Because US schools teach that by asking for two page essays about a Hiaku, or five pages for a 50 page novella. How about the first-grader's assignment of two pages describing how to make a PB&J?