Aggression is an instinct, even as sex is an instinct. Thus all efforts at eliminating the causes of aggression can be seen in scientific terms as inherently doomed efforts to prevent a instinctual discharge by means of eliminating its typical eliciting stimuli. To the extent that the efforts to eliminate the eliciting stimuli succeed, the discharge of the aggression becomes less predictable and often more dangerous. Skill in aggression will be needed from time to time, especially by those lacking skill and will. The solution is to ground aggression in a ritual expression that also prepares it for functional application.
Aggression has three purposes in nature.
First, to spread a species out over territory so as to not overload an eco-system. Second, for rank within the hierarchy of a social group. All social groups have hierarchy. And third, for reproduction. Classically this means two males fighting over the female, but it also means the female defending her young.