The statistic folks are citing for the 90% or 10x is based on a study of how much attitude information is conveyed non-verbally during a negotiation.
Engineering should be more about meaning content than attitude content, and engineering workshopping should not be a poker game.
The stat is not about conversation content, but conveying attitude. The study found attitude was conveyed 55% nonverbal, 38% vocal, and 7% words only.
By that study, using the telephone would be 55% info loss about attitude (tone and words convey 45%), and using video chat adds facial expression (majority of non-verbal attitude). Attitude info, not meaning info.
So no, it's not 10x more info in person, even for the narrow case of conveying negotiation attitude blind over telephone, plus most non-verbal attitude is conveyed by facial expression which comes through on video chat.
