There are meaningful ethnic disparities between say, Black and White Americans; and those are the categories because national origin is a lot harder to measure, particularly for the descendants of people enslaved before any of the countries of modern Africa existed.
That’s how ridiculous it was/is.
https://en.m.wikipedia.org/wiki/Definitions_of_whiteness_in_...
edit: typo
At best, they try to whittle down someone’s perceived socioeconomic status, strength of family, and “cultural” values into a group with others where you share (very roughly) the same quantities of the aforementioned qualities.
Even place of birth is probably not very informative in 2023. You could be the child of poor immigrants who came to the US via chain immigration, or the child of factory owners who could afford to pay $60k per year for you to go to grad school in the US and obtain an H1-B, or even have enough to invest and get an EB-5.