That may "answer" a specific question. And all llms can do as they include manpages in training data (and any Agentic thing can search) however the value in reading documentation is that one can find different angles by learning about different options, which allow tontackle problems from a different perspective. The answer to a question is constrained by assumptions which are part of the question.
My experience with LLMs is that they often give me different angles that I didn't think of.