Do you think it's enough to say "Customer Collaboration over contract negotiation"?

You will never ensure will deliver value just because you collaborate with the customers. You may build what they want but not what they need. Or you may build something wonderful for them and yet return no value to the business.

My point is not to say Agile Manifesto or Scrum are wrong. I am saying they are insufficient to deliver value. Solid product management skills are required for that. Therefore, I long for a Product Manifesto.