Excellent points and some of the reasons I hate doing the whole Karen meme thing. I have often written about how sexism plays a toxic role in public discourse even among liberals and progressives.
Time and time again I see women mocked for being who they are and not for the things they say or do.
While it is surely important to acknowledge white women possess privilege they can abuse, the Karen meme phenomenon in my opinion seems to be leaping beyond that.
And I think you hit the nail on the head with the hammer of how and why.