KarinsDad said:
Sorry, your POV makes no conceptual sense. The PC with 60 hit points gets clipped hard by the 50 point attack, but gets killed by the 100 point one. The abstraction is still there. But the larger attack is still larger.
You ignored the rest of the point. You contend that 50 points of damage is stronger than 100 points of damage but fail to realize that because the system is abstract, that might not necessarily be true in the same way that someone with 100hp might not be 'tougher' than someone with 50hp.
For example, take a high-Con Barbarian and a low-con Wizard. Now imagine that someone takes a dagger and slits their throats. They both die. It didn't matter what the Barbarian's hp were so high or that the dagger only deals 1d4 damage, he's just as dead as the Wizard. This is why we have rules for Coup de Grace, because it makes no sense for the Barbarian to survive that wound.
Consider different sources of damage. A Rogue with a dagger sneak attacks, a giant bashes in your head with a tree trunk or a Wizard unleashes a bolt of lightning. Which one is 'stronger'? Technically, all three of them should kill you, it doesn't matter if you're stabbed through the eye, bashed to a bloody pulp or fried from the inside out. Why ANY PC survives these attacks isn't about how tough they are: as the PHB states, Hit Points are about the ability to turn aside, avoid or minimize the effects of a blow in order to keep fighting.
What is the difference between a 50hp sneak attack and a 100hp sneak attack? You got stabbed in a less vital organ? He meant to hit your skull but only managed to plunge a dagger into your chest? Neither. The difference is that the Barbarian saw the 100hp attack coming and knew to shift slightly to take the blade in the shoulder unlike the wizard who hasn't trained in the martial arts and doesn't know the trick and thus got stabbed through the heart (or close to it).
The 50hp sneak attack does less damage, not because the assassin's dagger is somehow smaller than other daggers, but because of the wildly variable situation of combat (which is, incidentilly, why these rolls are random). The Barbarian saw the attack coming sooner and was able to twist out of the way, perhaps pulling a tendon in his leg but not taking the dagger in the shoulder. The Wizard saw the blow coming sooner but still how no idea about how NOT to become a shish-kebab, so he gets skewered.
The attacks aren't 'stronger' or 'weaker', a blade is a blade and a lightning bolt is a lightning bolt. What damage and hit points represent, respectively, is the character's skill in killing and living. The higher the damage you inflict, the harder it is for someone to turn the blow aside, the more skillfully you have made your attack. The higher your hit points, the greater your ability to avoid blows that should, by all rights, end your life.