The single biggest issue I've noticed is that body language communicates a lot, and in remote environments you cannot see this. You don't feel at all invested in the other person either, and I've noticed people multi-tasking instead of listening to what the other person is telling them - often followed up with a "Sorry, I missed that. Can you repeat it?"

As another example, I've worked with some people who are quite confrontational and dare I say, aggressive, on camera, and have raised their voice a couple of times in the past. This same person has very different interactions in real life, a lot more empathy, where it becomes apparent the other person is in fact, an actual person with emotions.