The historical idea of "skin culture" suggested that all white people shared a single, unified culture just because they have similar skin color. But this idea is easily debunked because white people come from many different ethnic backgrounds, like Irish, Italian, Jewish, and more, each with their own distinct traditions and histories. It's also rooted in colonial slaver history, where the concept of a mythical "white culture" was used to justify oppression and dominance. America today is composed of both colonists and immigrants, so there is no basis for the case that this exists today anywhere in America.
If that is the case, then yeah, “skin culture” is a dumb concept. People groups have historically been delineated by nationality, not skin color. Then there are subcultures within nationalities by region, religion, economic class, and urban/rural delineations.
Chattel slavery erased these delineations for African slaves, so they just became “black” rather than Nigerian, Kenyan, Cameroonian, etc. Somehow, this clumsy, broad brush identity solely by general appearance spread to every other group.
The "white privilege" refers to the advantages people seen as white often get in society, like easier access to jobs or fairer treatment by police. But this idea is equally debunked, mostly because it oversimplifies complex issues by focusing primarily on race without considering major factors like class, culture, or personal experience. Both of these postmodern concepts fail to recognize the diversity within racial groups and how actual privilege and culture work.
Actually, this concept of “white privilege” originated entirely from a brief essay titled “Unpacking the Invisible Knapsack” authored by a feminist seeking to spread her insights on gender inequality over to race. The essay lists various examples which can all be distilled down to what I would call “minority disadvantage” rather than “white privilege.” Ever since her essay, self important hacks have taken her observations and run with them well past the end zone (think Forrest Gump).
The only reason I can see why these shrill white "liberals" perpetuate the idea of privilege is to hold on to the myth that their skin color somehow makes them more than what they really are.
At risk of oversimplifying the complex, I believe this is the result of the rise of critical theory (race in this case) in academia occurring simultaneously with the decline in traditional religious dogma. “Nature abhors a vacuum.”