Who is the "some guy"?  A ghost writer?  "Amoris Laetitia' has MORE authority BECAUSE hundreds of bishops were meeting to discuss it.  The documents of Vatican II REQUIRED Papal Synods [that is what this is called] to be held regularly [the pope with the bishops], just as it had occurred in the ancient Christian church.  Papal synods of this kind were held almost until the time of the Reformation.  One of the strongest popes of the second millennium, Gregory VII, held such papal synods regularly, and obviously he did not think they were injurious to papal authority.

Through the whole first millennium the popes wrote no encyclicals nor did they define any dogmas of the faith.  The popes of the first millennium did not exercise a universal government of the whole church.  The popes in their capacity as bishop of Rome and successor of Peter were the BOND OF COMMUNION for all the other local church and the bishops, the successors of the Apostles.