This implies that body language is accurate and useful which is not always the case. I'd argue that many who legitimately don't wish to be on camera have very good reasons for this. I do not enjoy being on camera or even talking on the phone. I also have ADHD which makes it very difficult to just sit still and listen/watch an AV feed for a significant period of time even if I know that what is occurring on that feed is very important. My brain literally doesn't care what my mind thinks/knows it's going to do what it wants/needs to do which is fidget, search for sources of stimulation, and in general do all kinds of things considered "rude" to do when having a conversation or attending a meeting. Nevermind that I'm absolutely still paying attention, but I can't JUST pay attention. A lot of this hesitation to appear on camera in situations like mine isn't because I don't actually like being on camera, I don't care, but the negative reactions me being on camera can cause because someone doesn't know me and my specific uh... "issues" means that I just prefer not do so if possible.

I don’t know about etiquette, but body language is generally not how I want to be viewed during a hiring process, on screen or in person. I’m not particularly talented at making appropriate eye contact, or not flailing inappropriately, or keeping my coffee mug from crashing on the floor. I’m very talented at engineering software. I’m sure many businesses would agree I’m not a good fit, and… well, too bad for them.

Quoting myself: I very seldom feel inclined to refuse. That said, interviewing for my current position (fully remote team), I was given the option of video or voice call, and I chose voice. I chose that cautiously because I knew it might be offputting but I also knew it might be a good indicator of my prospective team’s culture if it had been offputting. Fortunately that wasn’t an issue!

And I now do a video chat about once a week, which isn’t particularly demanding, and it’s generally a positive experience because we work well together… but I do take an hour or two to decompress afterwards.