Maybe because you treat your subordinates in that manner? You actually sound a bit like the whiny one.

Say that again. I couldn't hear you over the sound of you stabbing your colleague in the back.

Evidently, she is highly competent at undermining. You underestimate her skill at that at your peril. She’ll probably be your boss soon.

Yep, I agree. I came across people like that a few times as a consultant. They usually gossip about other people to the boss all the time, making themselves sound great and the other people sound bad. I would recommend that you find another job because she will create a shitheap just so that she can be at the top of it and then she will maintain that position at all costs. The problem you have is that evidently the boss believes her.

Maybe your excessively negative attitude and comparing yourself to others has something to do with it?

Some people appreciate the tongue that the brown noser is using while down there.

well, you do have to look at what your coworker does better than you

Maybe shes like Michael Scott. Seems to be a complete moron but is really a genius who plays dumb for amusement