So it's a list of things that may be done if we have an (almost mythical) good manager at hand and the organization in the company is right? Not a list of concr

So it's a list of things that may be done if we have an (almost mythical) good manager at hand and the organization in the company is right? Not a list of concrete responsibilities that just come with the position and if the guy doesn't fulfil them he's outright incompetent? Then again, what is the difference between fundamental responsibilities of project and product manager? The ones that need to be done by one and cannot be done by the other.