like all things, how well one weapon does on killing is, ALL in where the bullet/broadhead is placed
and not a (legal to hunt with) gun or bow is made that doesn't take a human behind it
and the fault in that is, humans are well, NOT all created equally
some will practice more and be MUCH better shots than others due to there willingness to practice and ONLY take shots they KNOW they have a highl odds of making a quick clean ethical kill, and they all know what distance they are accurate at and what range there weapon of choice is capable of killing cleanly at!
SO< when you ask what is more ethical, that is and will always be a loaded question that comes down to the HUMAN beind each weapon , there skills and there mind set on what IF they are ethical to start with!
bad shooters of ALL weapons exits and when your trying to kill things that are trying to elude you, THINGS beyond ANYONE"S control can happen and cause a BAD shot and or wounded animal and suffering that comes from it
which brings you back to that HUMAN behind the weapon
SOME will do WAY more than others to try and correct any BAD shot they make, and others will just NOT care and move on to try again and NOT finish what they started
so again, its NOT realy the weapon as it is the human behind it, on how well one can be used over another
a bow and arrow/broadhead places in a vital will kill just as a bullet placed there, minus the shock value a modern weapon has
BUT shoot a animal in a non vital with either and you can and will have a animal that suffers and MIGHT die, or might live
? its NOT a black and white question here! too many variables