As I understand abuse, It's often easier to discuss that which abuse is not- it isn't about anger or aggression.
Abuse is about control.
Abusers abuse because it rewards and maintains control. It garners resources to the abuser to allow them to continue their behaviour and to bolster their flagging self confidence and ego.
I have observed three main ways abuse works, firstly there is the abuser who abuses as a lifelong pattern of abuse, this is sometimes referred to as systematic abuse. it is the way they interact with the world and with their main relationships. They may also have personality disorders, a colloquial expression is mental and physical "terrorists". Others abuse because they have hit a crisis in their lives midlife or other, this is situational abuse. They are in an A and wish it to continue. Finally there is reactive abuse, the target reacts back to an abuser by creating abuse patterns, in my own case I called this part of me "screaming banshee".
Certain abuse patterns particularly systemic ones have a lifelong component and may require intensive treatment. In my case as the target of such abuse IC, twelve steps, DB and attendance on an abuse manangement and recovery course.
I also know that intoxication (alcohol and substance) can intensify abuse and abuses may use this an excuse for the abuse. I could not help it the *substance* made me. There is a choice to manage the substance, and abuse is targeted at close R members and not generally. If Most Rs can be managed without abuse then substance use is no excuse for abusive behaviour.