Wrong, the sharper , the pointier the easier the penetration on bone, ply wood , skin, meat, whatever.
Its all pressure. With enough you can make something dull and flat penetrate steel. With a given velocity, or pressure or kinetic energy, whatever you want to call it, the pointier or sharper the easier the penetration.
I can cut through the ribs of a deer with a simple sharp knife, try it with a dull one.