Stretching can be beneficial for many reasons, including but not limited to:

• Increases your flexibility. This is very important, especially since when we age, we naturally have reduced mobility. An increase in flexibility can help delay this.

• Increases your range of motion. Having full range of motion just means having full movment potential of a joint, usually of its flexion and extension. So logically, having an increased range of motion would give you more freedom of movement.

• Improves your performance in physical activities. According to Healthline, doing stretches before an activity (a sport, for example) betters your performance in said activity.
  

• Increases blood flow to your muscles. Performing stretches might improve your circulation, or blood flow to your muscles, which can in turn reduce muscle soreness.