I understand kinetic energy, it's kinda baked into my career, but it gives almost no prediction to results on target. KE doesn't describe how the bullet transfers its energy to living tissue, only what it's doing at any given point in the direction vector of its trajectory.
A magnum caliber with a mono bullet will have far more kinetic energy than a moderate caliber with any bullet. But the level of damage to vital organs is often inverted if you pick a good expanding/fragmenting bullet for said smaller caliber. That's because what the bullet does once it enters tissue matters far more for rapid lethality.
This is why Q and Kevin B, who have designed cartridges around monolithic bullets, advocate for spinning them as fast as possible without the bullets coming apart. Because the standard wound channel of a mono bullet is pretty abysmal, whereas if you ramp up the RPMs it has an immediate and drastic effect on permanent wound cavity. You're displacing far more tissue with a centrifugal energy that is off-axis to the direction of travel.
The same thing happens with a fragmenting or tumbling round, where massive tissue damage is caused by "pieces" of the bullet breaking off and continuing on their own skewed trajectory through tissue. You also gain the advantage of transferring far more of that beloved KE to the animal, where a much "tougher" bullet, or a solid, will retain (i.e. waste) that energy upon exiting the animal, therefore causing far less trauma.
Most hunters would be better served with a smaller caliber and better bullet vs maximizing their KE with a magnum unnecessarily. Because you're right, you can shoot a bullet that does far more tissue damage than desirable when you get into magnums. So imagine taking a bullet design that is maximized for lethality and putting it into a smaller cartridge that is easier to shoot, but has far less KE on paper.