I guess Native American is a made up concept too then, since they were divided into different tribes that spoke different languages?

<‘Whiteness’ is just a made-up concept that describes dozens of distinct ethnicities and cultures.

The two are not mutually exclusive. Whites can have distinct sub cultures and still have a broader shared lineage. This isnt a hard concept to grasp, but denying it is a well known Jewish tactic meant to divide and conquer. Forensic experts readily identify badly decomposed bodies as white, black or Asian based on anatomical distinctions and DNA analysis.