Actually I have answered that question a number of times.
The system is top down. Laws and policies have been enacted and changed. I was alive when a black man could be arrested for having a reckless eyeball. Now I have a half dozen friends who are black men with white wives. There is no position in America that is legally off limits because of race and/or gender. Yes, The Marine Corps does have some combat arms positions that are gender restricted but race restrictions are long gone. The "system" has been corrected. There is still racism and sexism but it is bottom up from individuals and their attitudes, not top down with the force of law. Bottom up is where I've always done my work.
I have driven over a hundred miles to march in political protest of a forfeiture fishing SWAT raid that ended with a man's death. Nothing illegal was found in his home. So I have gone out and marched in the cause of social justice. My primary method is less formal and more personal.
I have always called out racism and discrimination when I've seen it in real life, in some cases a risk of adverse consequences beyond people calling me names. I try to be an example. I have no way of knowing if I've been more effective than Internet oracles of social justice. There's a good chance that I have since I don't think many minds change because of internet arguments.
About 35 years ago I spent many evenings listening to an old black woman in Georgia tell me what a bunch of evil bastard white men are. I let her dish it out because I wanted to hear about her experiences. She was not accustomed to that and it was good for her to get it off her chest with me. That was sitting right next to her, not from behind a keyboard. It was effective communication because it was the personal interaction that I prefer. She had experienced the burning cross and gunfire. I knew black men who told me that when the police stopped them there was a, "Is that your boss man's car you're driving boy?" "Yessah, it's my boss man's car." That shit doesn't happen any more. No doubt there are some who wish it did. That's where the work is.
The assumptions made about me and the names I've been called over the internet by people who know nothing of me except my original sin of having white parents are not helpful. If I find it unhelpful I doubt that it will have better results with people who really need it. I see a difference in standing up against injustice and calling everyone to the political right a racist, fascist, Nazi and such. It just gets an oh please, go f*k yourself with that crap response, often unspoken but the thought is there. Yeah, great approach.
So again, the answer is that I think walking the walk within my circle of influence is more influencing than talking the talk to whomever it may concern on the internet. It's not for everyone. I understand that. You badly misunderstand me if you think that my criticism of bad tactics is a defense of social injustice. It's less a matter of me telling anyone what they are doing is wrong than suggesting they assess their results with their methods. What was an effective tactic to get change in the system may not be effective in winning hearts and minds of individuals and changing attitudes. That is where the effort needs to be at this time, in my opinion of course.