In my estimation he is not. I "remember" office for good and bad, for most of the time even when I communicated with folks next door/nearby i would still fallback to chat. Water cooler talks is what I miss actually, but if you meetup couple of times a year - you get the feel of those people. Also now that people got so used to streaming more, its often much easier to pair more effectively (if one person drives some stuff, the other person can do other checks etc.)

I do not think 10-15% degradation is underestimated.