The Kettlebell Swing is one of MANY exercises that can drastically help improve one’s athletic ability. The reason being is that it places a large emphasis on hip flexion and extension, which is an important movement pattern seen time and time again from various athletes during their sporting event(s), especially when running, jumping, & changing directions.
Not only that, but this exercise also places a large emphasis on improving the athlete’s rate of force development (RFD), which is crucial when considering the athletes who have to produce large forces quickly (i.e. track athlete: @noahjamesstrenn).
One thing to note is that the kettlebell is driven by the forceful action of your HIPS and NOT your shoulders/arms. Your upper extremities should really be doing very minimal to no work at all aside from gripping the handle! Hope this was helpful!