Design Validation is a pivotal stage in the product development cycle. I have experience regarding process validation but not design validation. However, user needs need to be met because that is directly coming from the customer who is providing the insight and need for such a device with x functionalities. If a user need is not met then the Engineering teams responsible needs to reevaluate and plan to meet such needs. Just as Parth mentioned, the goal of validation is to make sure all the user’s inputs are met. Otherwise, the product may not fulfill the needs of the customer. Potentially make the product sell less or have to be revised which would create more added time.