The question was margin of error the answer is more energy gives greater margin of error. A shot 4” too high or low with a larger faster bullet will kill faster than a smaller slower bullet. If you’re so convinced you are right please use a very small marginal cartridge for dangerous game as a demonstration.Your energy equation? How does e=m*v^2 demonstrate killing?
Where are you getting this “younger” wants view, and younger than what?
The laws of physics can’t be changed. Noted. So what does that have to do with 30 cal vs other choices?
Younger meaning hunters from the outdoor channel & hunting forum generation. The power of advertising is remarkable. The newest & latest must be best. In many cases it is much better modern optics, metallurgy & manufacturing as well as clothing & packs make a huge difference.
The 6.5 Creedmoor isn’t a revolutionary change vs the old 270 for hunting.
But by all means demonstrate your confidence- a 6mm shoul be perfect for a Grizzly ar cape Buffalo hunt.