Her videos are average but not terrible.
The complaints against the videos themselves are more technical (she cherry picks unrepresentative data, she doesn't provide good evidence for her claims, she flat-out misrepresents some games in order to try and make a point).
The larger hate for her is how she acts and treats people. She's a closed minded intellectual bully who has never interacted with her critics at all. If anyone disagrees she simply claims they're "inciting harassment" towards her. On one occassion she put the faces of a series of youtubers up on her twitter and says "these guys are organising harassment of me" with absolutely zero evidence to support her claim (at least 2 of them have explicitly told their audiences never to contact or insult her)