I hope this side is for people who say yes! There is a purpose! I think that the whole point would be that free will is needed to try and find the best definition of justice and right from wrong. The beauty of it is that you can show all the sides of an opinion, so that life has diversity and purpose to it, to make sure that there is a balance (equality), and when needed the balance is upset, like if a world like in the movie "The Giver" existed, where they were all equal, but they were all being held back.
Without the ability to be perfect we will all eventually hurt each other gratuitously and treat each other unfairly which is only good for those who have the advantage while life should give you an equal shot at succeeding. There is no good reason for making great suffering pain and misery happen to bring yourself pleasure. That is extremely unfair and you wouldnt want to be on the receiving end of that and to accomplish the goal of avoiding that fate you need to resist the urge to take the advantage yourself. Change starts with you. We may not know what people deserve because we dont know what its like in their minds but we know many things they dont deserve. And what they dont deserve or possibly dont deserve is much more important than justice which is just revenge. If you choose to punish all criminals the same way for a crime your giving many much more punishment than what they deserve while giving some much less punishment than they deserve. So justice is not achievable as we dont know what it was like for the criminal to do the act or why they did it. Results arent all that matter. Intent matters just as much if not more than results when trying to determine whether or not something is punishable. I dont believe accidents that could happen to anyone are so punishable just because the results when the "criminal" had no criminal intent.