I answered the next comment down the chain, but I agree with you. As framed, there is no satisfactory solution to making a question "good".
Improving question quality could however be a product goal for StackOverflow, or for a company focusing on writing tools (Grammarly, Textio,...). The book describes a process for turning that vague product goal into a more tangible set of metrics, which lead to choosing an ML approach, and iterating on it.
Eventually there is a finished prototype, for which you can find a GitHub link in the PDF preview. It has definitely not solved how to evaluate if a question is "good", but aims to provide a narrower set of recommendations (the first chapter actually dives into an approach for this).