"Where there is no vision, the people perish..." ~Proverbs 29:18, KJV
The most practical advantage of vision is it sets a direction for our lives. It serves as a road map. In this way, vision simplifies decision making. Anything that moves us toward the realization of our vision gets a green light. Everything else is approached with caution.
Vision will prioritize your values. A clear vision has the power to bring what's most important to the surface of your schedule and lifestyle. A clear vision makes it easy to weed out of your life those things that stand in the way of achieving what matters most. Vision empowers you to move purposefully in a predetermined direction. Once you have clarified your vision, or visions, many decisions are already made. Without vision, good things will hinder you from achieving the best things.
My observation is that people without clear vision are easily distracted. They have a tendency to drift from one activity, pleasure, or relationship to another. Without vision, there is no relational, financial, or moral compass. Consequently, they often make foolish decisions, decisions that rob them of their dreams.