Today I had some insight in what social justice really seems to be trying to do. I'll use neurodiversity as an example because it's less likely to lead to bad-faith arguments.
Let's say you're in the (archetypical) position of a king. You're programming the rules that a group of people will live by, optimizing for the well-being of the group itself.
You're going to shape environments for people. For example you might be running a supermarket and deciding what music it's going to play. Let's imagine that you're trying to create the optimal environment for people.
The problem is, since there is more than one person that is affected by your decision, and these people are not exactly the same, you will not be able to make the decision that is optimal for each one of them. If only two of your customers have different favourite songs, you will not be able to play both of them. In some sense, making a decision over multiple people is inherently "aggressive".
But what you can do, is reduce the amount of damage. My understanding is that this is usually done by splitting up the people as finely as possible. You might split up your audience into stereotypes for "men", "women", "youngsters", "elders", "autistic people", "neurotypicals", etc. In this case, you can make a decision that would be okay for each of these stereotypes, giving your model a lower error rate.
The problem with this is that stereotypes are leaky generalizations. Some people might not conform to it. Your stereotypes might be mistaken. Alternatively, there might be some stereotypes that you're not aware of.
Take these 2 models. Model A knows that some people are highly sensitive to sound. Model B is not aware of it. If your model of people is A, you will play much louder music in the supermarket. As a result, people that are highly sensitive to sound will be unable to shop there. This is what social justice means with "oppression". You're not actively pushing anyone down, but you are doing so passively, because you haven't resolved your "ignorance".
So the social justice project, as I understand it, is to enrich our models of humans to make sure that as many of them as possible are taken into consideration. It is a project of group epistemics, above all.
That means that good social justice means good epistemics. How do you collaboratively figure out the truth? The same laws apply as they would to any truthseeking. Have good faith, give it some probability that you're wrong, seek out to understand their model first, don't discard your own doubts, and be proud and grateful when you change your mind.
The problem is that reducing the amount of damage is not the same thing as maximizing value. It's not utilitarian.
If you are faced with making a decision that gives 99% of people +1 utility but 1% -10 utility, an approached that targets damage reduction means that you make a choice to leave 0.89 utility for the average person on the table.
So the social justice project, as I understand it, is to enrich our models of humans to make sure that as many of them as possible are taken into consideration.
Giving someone consideration is not enough from a critical theory perspective. Consideration is not equity. Equity is about also giving them power to take part in the decision making.