When you operating in the territory of things that are harder to write down than explain in person; teleconferences are simply not good enough.
A question has to be why things are harder to write down than explain in person.
Perhaps you find the act of writing down too slow and so you lose your train of thought, something that can be overcome through understanding your thinking style and applying structure and practice (eg. see the Pyramid Principle).
Perhaps the problem requires you to walk someone through a set of diagrams/screens - in the case of diagrams, your style maybe to annotate as you explain. Yes, video means you can easily miss the visual cues as to whether the other person has or hasn't understood the point etc., so we just need to get used to asking and giving confirmatory feedback.
On a slightly different tack; back in the 1980's (before cheap mobiles and easy access to email) I had a PA who made great use of ansa machines to the point where if you picked up a call from her, you often got the introduction: "this is for your ansa machine, not you..."
But yes, there are benefits to be derived from simply spending time together with other people in the same geographic location. For one company I worked for that meant having to visit a rather nice french chateau a couple of times a year.
Biting the hand that feeds IT
