People are the most important factor for successful adoption of Agile methodologies. Failing to pay attention to team dynamics and individual skills can lead to failures in Agile projects. Key reasons for failure include not building an Agile team properly, having the wrong team composition or lack of experience, and not understanding Agile values. To prevent failures, organizations should ensure team members are self-organizing, communicate well, continuously improve their skills through training and education, and are fully committed to Agile principles.