How much time has been wasted over the years trying to serve the needs of multiple masters? One person wants to see a feature implemented one way and another person wants it done completely different. The team vacillates back and forth until they run out of time and then no one wins. Agile channels all the dissenting opinions into a single voice or proxy and provides a clear message to the development team. This single voice provides clarity to the team and allows them to focus on a single goal.
Another typical distraction amongst many project teams is too much time spent in meetings. Agile limits meetings to generally one brief standup meeting a day and longer planning and retrospective meetings on the bookends of the iteration. By limiting the time spent in formal meetings Agile teams are better able to focus on getting work done in a timely and efficient manner.