A product vision is like a compass. It’ll help you and your team make decisions, and steer the product towards your destination.
Building a compass is hard. It requires experts and a team. Product managers often focus too much on making the compass (creating a vision) and not spending enough time using the compass to navigate.
As a product manager, your most important responsibility might not be to create the vision but to hold it. To remind everyone about the vision, and help them use it to make decisions.