A lot of issues you bring up. But I think the most important is about how to think about evidence.

Say we discuss the existence of black sheep. Your evidence against black sheep is to show me a 100 white sheep and say "look none of them are black. Black sheep don't exist." Then you produce a single black sheep as a counterpoint and say "See, black sheep exist. This one is black."

Would it be reasonable for you to then argue: "Okay we we got two pieces of evidence, one showing there are no black sheep and one showing there isn't. Let us call it a tie. The issue cannot be settled. We have equal amount of evidence on both sides."

Of course confirmation bias exists, but you cannot use the existence of confirmation bias to argue those who disagree with you are suffering from it.

I like to take a Baysian view on reality. We can never know anything for certain but we can say something about probability of certain things being true given differen observations. Many people of color complain about experiencing racism, and we can find various studies which confirms this.

There are many explanations for this. It could be a liberal conspiracy. I could be minorities who simply cannot accept their own deficiencies. Or it could mean systemic racism is actually a real thing. I would assume the latter seems more plausible.

Likewise I think it seems entirely plausible and logical that many people have an investment and desire to prove that it is not true. Particular libertarian and conservative ideology gets a major philosophical problem if systemic racism is real. Why?

Because both want minimal states, where individuals go about their business with minimal state intervention. That ideology becomes very hard to argue if it turns out that systemic racism has major impact on people. It means the liberterian/conservative idea that everybody is a captain of their own destiny doesn't quite work out. It is similar reasons why they are invested in disproving that inequality matters.

You see historically how libertarians argued that poor people were simply more stupid than rich people. Admitting that there was major disadvantages to being poor in having success in life would imply that government ought to commit resources to given everyone a more equal chance in life. This would run completely counter to conservative/libertarian ideology.

I don't think you can rule out that such ideological convictions don't drive a strong confirmation bias and search for whatever research and literature disproves any sort of disadvange experience by any group of people. The search instead becomes focused on ways of blaiming the victim. Finding ways to prove that e.g. poor people are simply lesser people, and this explains their poverty. That society plays any role goes completely against their ideological convictions.