Bendy Bones are a lot more than just a subdivided Bone; they are based on a Bezier Curve, so you can bend them by manipulating the two ( per Bendy Bone) ‘handles’. This general behavior is really hard (if at all possible) to acchieve without using Bendy Bones, but if you have a specific situation, you can make a rig with ‘normal’ Bones, that does what it needs to do. But it would probably involve more Bones and some (quite a lot, depending on the situation) Constraints.
