Why did all the ancient arrows have feathers on them?

Arrows play a role in balancing and keeping direction in flight. Feathers are glued to the back of the shaft of an arrow to balance and maintain the direction of the arrow in flight. Typically, arrow feathers have a streamlined profile, which is very aerodynamic. Plastic arrow feathers are made of soft, flexible pieces of plastic, and it is by far the choice of most archers. Its benefits include being inexpensive, quieter in flight, and easy to bond, long lasting, not afraid of water, and basically adaptable to all kinds of weather, making it a great choice for bow hunting. However, there are some major shortcomings of plastic arrow feathers, first of all, the weight of plastic arrow feathers is heavy, it is three times the weight of feather arrow feathers in the same size. And because plastic arrow feathers have a smooth surface, they are less stable in the air than feather arrow feathers with a rough surface. Feather arrow feather is made of natural feathers, the cost is very expensive, it is basically 4 times the price of the same grade of plastic arrow feather, if the special shape of the feather arrow feather is 10 times the price of the same grade of plastic arrow feather. Feather arrow feather is very afraid of water, in the rain or humidity of the weather will affect the quality of flight. However, the biggest advantage of feather arrow feathers is that they are lightweight, usually 3 pieces of 4-inch feathers weigh only 8 grains, while the same plastic arrow feathers weigh 24 grains. Feather arrow feathers hold their flight position better than plastic arrow feathers. Depending on the placement of the feather, they can be categorized as straight, offset, or spiral Straight is when the feather stays parallel to the shaft of the arrow. The offset type means that the bottom part of the feather is straight and parallel to the arrow shaft, but the top part of the feather is deflected from the shaft at a certain angle, usually by 4 degrees. The spiral type means that the feather is bonded to the shaft at an angle and has a greater rotation. Both deflected and spiral type arrows will rotate themselves while flying through the air. The difference between these is like the difference between a bullet fired from a smoothbore gun and a bullet fired from a line gun. Characteristics of linear arrow feathers: fastest flight speed, lowest air resistance, cheap bonding, able to match with all kinds of archery platforms. However, the ability to maintain flight attitude over long distances is weak, and the balance is not good when using a fletched arrow. Characteristics of offset arrow feathers: better balance for arrows with arrowheads, less air resistance, can match with most archery platforms, and can maintain a good flight attitude at longer distances. However, this type of arrow feather will reduce the speed of the arrow and affect the kinetic energy of the arrow. Spiral type characteristics: the most stable flight attitude, so that the whole flight process can be kept stable, significantly improving the accuracy of the arrow. However, it also significantly reduces the speed of the arrow, and the kinetic energy of the arrow will be reduced accordingly. Maximum air resistance. Can only be matched with some archery platforms.