I think where 2001-style projections of the future differ is that they hold up video chatting to be some end-all, be-all goal of future communication. As you say, audio only is more convenient. I'm a dirty tech person and I prefer text even when most of my friends prefer audio. But unless I'm putting my software engineer hat on, I'm not really thinking about "how am I communicating today is it video, voice, or text" I'm just summing up my situation (at home, in public, doing groceries, etc) and finding out how I can communicate with a person. With video, voice, and text all instantly available, none of us really think of one form as paramount, though we all have our preferences. Just like in real life, we all communicate in each other with different ways appropriate to our moods and our settings.