In not only ranked solo/duo queue, but normals as well, most teams lack one thing.
Competitive player Dyrus said that what most solo queue teams need to be successful, is for someone to take the role of the leader.
Teams without a leader figure, will run around the map, split up, and without vision, causing games to be thrown, despite superior team compositions.
Taking charge doesn't necessarily mean yelling at your teammates.
It's the concept of asking your teammates to group up, maintain vision, and work together.
A team that works together, can beat a team with a better composition that doesn't work together.