Animating in Blender by using the Graph Editor to make the movement arch of a bone nice and smooth is hard and time consuming. Better way to do it is if you could edit its motion trail.
Sadly this feature doesn't come in Blender by default. Thus, you need to buy an add on called Motiontrail3D.
It may feel daunting and stressful when using it at the first time. Because subjectively it's not intuitive. But once you get your hand on it, your animation will look smoother.