[Padme said:]
I was watching a show called The Evolution of the Lightsaber Duel recently and mark hamill said darth vader was originally supposed to say “obi wan killed your father” but they changed the line to say “I am your father” unbeknownst to hamill. Just thought that was an interesting aside.
From a certain point of view he did. In the sense that he cut off all his limbs, left him near a lake of lava and watched him slowly cook without using the Force (which can lift spaceships and support collapsed ceilings) to take him to a place of safety, where he could attend to his wounds and try to turn him back to the side of goodness and not domestic abuse and child murder. At least Han gave that a go in this one.