Question about bendy bone as a shapekey replacement

I try to make sure that the character’s body is not distorted and anatomically correct when moving the character’s joints.
There are too many to make shape keys for this, so I thought it would be much simpler and more accurate to control it through rigging.
So I searched and found that bendy bone would be suitable.

The idea is this :
Taking the pelvis as an example, make a bendy bone in the shape of an actual pelvic bone, then make it a child of the existing pelvic bone and control it with a driver.
Of course, this pelvic bendy bone does not deform its shape, and only follows the pose(transform) of its parent, the pelvic bone.

The reason for trying to use bendy bone is because, considering the movement of all XYZ axes, I thought that an actual skeletal object would maintain the body shape more accurately than rigging a few general bones.

I read the Blender docs, but there are only normal bone and bendy bone types.
Please advise if there are other types of bone or a better way.