Actually though…. A lot of the reason there is so much cultural appropriation going on is because ‘white’ has no culture. It might be a good thing for people to find out where they came from. It would be much better to be 25% German and bring some of that culture and tradition into their every day life than to be a white American who thinks it’s cool to wear a bindi. Just sayin.
…Generally white americans are the only one privvy to that knowledge. The point is not: “oh white people culturally appropriate” the point is, white people (and white Americans in particular) are the only group of people capable of doing this because the knowledge of their ancestry has not been systematically withheld from them. (see: slavery.) You’re able to look up in ancestry.com and see where all of your relatives come from for 100s of years. For many families of color, that line will stop at the first sign of interracial mixing. White people aren’t the only ones who are 22% irish, 18% german, etc…the whole world is that mixed. White people are just the only ones who have this information readily available via a few purchases.
Furthermore, you’re the only group of people who care about being 19x the same thing. See a dark skin person and have them say “oh I’m 15% german” and the majority of the population will laugh or say “no way.” but a pale person says: oh i’m 18% this other flavor of white and “OMG THAT’S SO COOL.”