In many countries, 16 year olds can drive cars

People on the cusp of adulthood should have the capacity to decide the government and policies that will be implemented as they leave school. Furthermore, many teenagers are much more politically invested and have a much more researched set of opinions on current issues than older adults do. 16 is old enough to have valid views on the world, and these need to be taken into account, particularly in the modern world where change happens so rapidly.