Ask HN: Why can’t we have LLMs writing documentation?

Everyone says documenting code is important yet no one seems to want to take the time to write such documentation. My question is wouldn’t it be possible to just let a LLM keep reading your repo and generate the necessary documentation? People already use LLMs to code and are trying to make LLMs work as full developers. If we expect them to work as independent developers in the near future, can’t we get them to at least write useful documentation first?