To each their own, but strong disagreement on that. I found the acting well above video game average (which, admittedly, I think is a low bar), especially Rost, Teersa, Erend, Avad, and Olin, along with some of the voice acting in the audio clips. Paradoxically, I thought Lance Reddick's delivery was as cartoonishly untrustworthy as it always is - it's the vocal equivalent of mustache-twirling.Aloy was cool, but nearly every other character not Lance Reddick has really bad acting...
I agree that Aloy's plot isn't actually as interesting as the back story, but that's not so much a knock on the plot as admiration for the back story. I could see where it seemed to be leading, but my jaw hit the floor when I realized exactly what happened for the world of Horizon to come into existence. For me, it was one of the most memorable turns in a video game ever. I'm sorry you didn't get that same experience.