I agree with you that identity politics is a curse that divides a nation. However, in the interest of fairness, it is important to note the justification for identity politics as articulated by its defenders.
When an individual faces discrimination or harassment because of their ethnicity, gender, etc., then it is logical, indeed imperative, that they would find other individuals in the same situation to garner collective bargaining strength. This is no different than workers' unions, the only differentiator being what is the group's unifying factor.
Rights are invested in the individual. This is the key foundational liberal principle in the West....a realisation achieved at great cost.
Indeed, the core focus of Western liberalism is individual rights but the ideology is mature enough to realize that, in the real world, such rights are bestowed, protected and enforced by institutions. Thus it becomes imperative to keep those institutions under constant focus of accountability.
The whole debate here is whether powerful subgroups have hijacked the institutions to deviate from the ideals of Western liberalism.
Its the literal reason why Martin Luther King mentioned content of character over colour of skin (and always marching behind the US flag)....and why that sits in direct contrast to what say someone like Ibram X Kendi says on the matter today.
Well, that's a whole subject by itself and there is a divergent view of history which I find amusing and interesting.
MLK was preferred by the white establishment over Malcolm X precisely because he was an ineffective, non-threat to them. Where Malcolm X demanded his rights "by any means necessary", MLK was obsequious and accepted the supremacy of the white establishment. All he could do was wish and hope and pray that the whites would pretty please find it in their hearts to spare some pity for the African Americans and give them more rights.
The white establishment and press were terrified of their worst nightmare, the angry awakened black man, and eagerly promoted MLK over Malcolm X as the voice of the African Americans. In the end, whatever MLK achieved was only what LBJ was prepared to offer.
The neo-marxist trap wants to harness colour of skin and other immutable characteristics that stray well away from classical or traditional liberalism for a reason....and stray away from original marxism (which had this has economic class struggle, regardless of immutable characteristic).
People will form a collective over whatever characteristic makes them vulnerable to inferior treatment. Whether it's color of skin, gender, ethnicity, or working status, it's all the same.
an agenda that wants to address any racism with counter-racism
Indeed, as I mentioned previously, any ideology will be hijacked by extremists on both sides. That is human nature and one can hope that the broader populace finds a middle ground in the long run.
There is just right and wrong (and the conveyance of this to sacrosanct individual rights to be enshrined in the republic system, and never up for a populist vote and a signficant counterforce to any populist coercion that builds up upstream to it).
That is why the US Constitution and the Magna Carta are two of the most important documents in modern history. Every country should adopt such protections and America is all the better for having its Constitution.
The problem, as always, is that laws are enforced by institutions and, ultimately, by humans, so accountability is paramount. Developed countries are closer to the ideals of Western liberalism because they generally have more robust mechanisms for accountability compared to developing countries.