Here’s a good paragraph by Philosopher Bear:
People imagine that they want vengeance, when really what they want is vindication. In many cases, I think, the reason victims want a long sentence (when they do want a long sentence- it is a mistake to think they always do) is because they want society to assert that what was done to them was extraordinarily wrong. We have been taught that “the longest possible sentence” is the way to do that. We have been hoodwinked into thinking that we want vengeance because it is easier to give people vengeance than vindication. What we really want, I think, is the repair of the world. We want to be able to see each other, and be seen, and to have the truth of it all. Inflicting pain is a poor substitute for a real resolution. It might be the only substitute available sometimes, but it is still a poor one.
As George Orwell has observed, we only dream of revenge when we’re powerless and because we’re powerless. Once we find ourselves in a position of power and revenge actually becomes possible, committing it becomes pathetic and disgusting.