I've found I trust people less who are staring at the camera, because they are prioritizing building psuedo-webcam empathy over actually looking at and following along with/understanding our shared screen.
I dunno. But at some point you can tell who's faking it. Sort of like someone who read How to Win Friends and Influence People and follows it to the letter- they use your name too often shoehorned into conversations and ask about your dog a little too early and enthusiastically with feigned interest.
Perhaps this is a cynical viewpoint brought on negatively from too many zoom webcam meetings!