Yes, very true. Having the camera off also means that we miss out on lots of non-verbal cues. I can't tell you the amount of difficult meetings I have had where people are edgy when the camera is off. With it on there is often a more relaxed vibe as people don't get the wrong end of the stick as much.
This can go the other way as well, thinking visual cues imply X when they actually imply Y. On the other hand, one can resolve most of these scenarios by asking the other party to elaborate and to keep emotionally charged arguments / personalities off the table, rather than assuming their emotional state and trying to play off of it or feeling attacked.
This is a huge part of why I prefer text. It would be one thing if people could misread my face or voice, then take my word for it when I tell them what I actually mean. But what often happens is they dig in on thinking they've struck it rich on some deep insight into my psyche and proceed to tell me what I really think.
Not everyone is like this. I can have a great time with people who compare inputs, see they diverge, and weigh the one that provides the most charitable view higher. This is usually my actual words, which I've been told sometimes comes with a "tone" that sends all the wrong signals. It turns out a lot of people read my usual pace--which can be way too fast at first--as anger or annoyance. When people focus on the words, it's obvious (by their own account) that I'm calm and enjoying the conversation.
It's usually a cue to take a deep breath and slow down. But it's hard to remember to do that from the start, and not everyone is willing to let the tone go once I take that control. And then the deep breath becomes part of the imagined anger/annoyance. It's made me wary of voice and video chat, and wary of people who prefer it specifically because they want to use the way people look and speak to determine what's going on in their heads rather than pay attention to their words.
