The history of racism in the US is long and complex. In essence we keep track of this sort of thing to try to prevent ongoing systemic racism. "You can't fix what you don't measure" and all that. It also doesn't need to be systemic racism per se. People tend to hire people like them due to unconscious biases so if your company is mostly "X" there are is a good chance it will continue hiring "X".

Here is one example that might be interesting: https://www.npr.org/2024/04/11/1243713272/resume-bias-study-...