There's nothing wrong with 'asking to see the manager' in most cases. I often ask because, having worked in retail myself, I know that some assistants simply don't have the authority or autonomy to make decisions. They need the back-up of a supervisor and I respect that. When I ask to see a manager in those cases, it's because I know the assistant is in a difficult situation.

Ditto demanding diligent care in a medical situation.

The so-called Karens we see are not the same. They're expecting everyone to dance to their tune and to jump when they say "jump". They often behave perfectly nicely to people like them (ie. white, usually) and are like Jekyll and Hyde to people who they perceive to be below them. Interestingly though, there's no real word for men who do this. In fact, there's rarely an outcry when men behave like this.

(And no - Chad doesn't cut it.)