One benefit of PI Planning is that it allows for faster decision-making by bringing together all the members of the Agile Release Train (ART) and the relevant stakeholders in a face-to-face (or virtual) event. PI Planning provides an opportunity for the ART to align on a common vision and mission, review the business context and priorities, identify and resolve dependencies and risks, and commit to a realistic and achievable plan for the next Program Increment (PI). By having everyone involved in the planning process, the ART can leverage the collective knowledge and expertise of the participants, reduce ambiguity and uncertainty, and make informed and timely decisions that support the delivery of value to the customers. (Must be taken from SAFe 6 Scrum Master resources) Reference:
PI Planning - Scaled Agile Framework
Planning Interval (PI) - Scaled Agile Framework
Preparing for PI Planning | Checklist for Scrum Masters and Product ...
Scrum Master - Scaled Agile Framework
Scrum Master role in PI Planning - ValueGlide