Brand strategy enables you to more effectively communicate with your target market by using a visual and verbal language they understand and connect with. This allows customers to recall more easily who you are and what you do, which builds trust and credibility when consistently repeated over time.
It also lets you more effectively shape your brand image. Or put differently, brand strategy enables you to define your brand in a way that your audience's definition of your brand aligns with your definition of your brand.
It can also help ground highly laudable missions, vision, value statements in the day-to-day of what your brand/organization/company stands for, making it more accessible to your target market.
Some brands even take those core beliefs that normally live inside internal documents—often never to be seen again—and bring them to the foreground, turning their beliefs into the basis of their brand’s entire communications strategies.