Customers are never pleased when told that they can’t get all the features they wish in release 1.0 of a new software product at least not if they want the features to work. If customers don’t differentiate their requirements by importance and urgency, the project manager must make these trade-off decisions and act as a bridge between the client and the development team overseeing complete execution of the project.
Your Tech team do not always know which requirements are most crucial to the customers, and customers cannot anticipate the cost and technical difficulty associated with specific requirements so this responsibility ultimately lies with the Project Managers and that is why they are hired.
A project manager has to balance the project scope against the constraints of schedule, budget, staff resources, and quality goals. One balancing and prioritization strategy used worldwide by many successful Project Managers is MoSCoW. A useful technique used in business analysis, and software development to reach a common understanding with stakeholders on the importance they place on the delivery of each requirement.
All requirements are important, but prioritize them on the basis of MoSCoW: Must Delivered, Should Delivered, Could Delivered and Won’t Delivered.