I fail to find anything derogatory or sexist in labeling white priviledged women "Karen"

[JonLP24]

71. I don't use it myself

This is what I could find from dictionary.com

Karen joins a trend on the internet in the 2010s of using a first name to make fun of certain kinds of people. A Becky, for example, is a stereotype for a “basic” young, white woman, while a Chad, in other corners of the internet, stands in for a cocky, young “dudebro.”

But, why the name Karen? Karen has widely been credited to Black Twitter in the 2010s. Another suggestion is that it comes from a 2005 bit by Dane Cook called “The Friend Nobody Likes.” (The friend was named Karen.) An additional explanation is that it comes from the character Karen in the 2004 film Mean Girls, who’s the subject of the popular quote: “Oh my God, Karen, you can’t just ask someone why they’re white.” It’s even been put forth that Karen comes from the even earlier 1990 film Goodfellas, in which one of the characters is named Karen.

Whatever the origin of the slang, the name Karen, apparently, is popularly thought of as a generic-seeming name for a middle-aged white woman of a certain generation. According to Social Security data, Karen was indeed the fourth most popular name for newborn girls in the 1960s, peaking at #3 in 1965.

(snip)

Karen further spread in 2020 amid the coronavirus pandemic and protests for racial justice. White women in viral videos—engaging in what was criticized as selfish or racist behavior—were shamed as Karens. The mayor of Las Vegas, for example, was called a Karen when, in a TV interview, she pushed to reopen casinos without social distancing despite warnings otherwise. Another notable instance was “Central Park Karen,” the epithet for a white woman who called the police on a Black man who was birdwatching in the Manhattan park, falsely accusing him of threatening her.

https://www.dictionary.com/e/slang/karen/

I don't use it but I understand that most people that use it are calling out racism.