Incidentally, this is a good way for people to actually take phone/voice calls seriously - when they're rare, it really means it's important.
I'm unconvinced.
I'm far from an advocate for pair-programming, but nevertheless I have seen how well it can work. It seems to me that that "shared brain" deep and rapid communication is extremely synchronous.
I wouldn't argue that it is required 98% of the time, but I also think that it being unnecessary 98% of the time is a exaggeration (if we measure based on the team's overall output somehow. Measuring it is of course impossible, but as a though experiment..)
This is true to a point, but is exacerbated by the current fashion for building software in ways that depend on very fine-grained collaboration around small tasks (and, more generally, the idea that teamwork is the only valid way of working on many problems). Coarser grained approaches are possible, and it's not too hard to find examples of them succeeding (e.g. many of the more traditional open source projects).
It's interesting.
Many proponents of remote work point out how much more effective it makes them.
The thing is that really doesn't matter. The thing that matters is how well the team works.
I'm a big proponent of asynchronous messaging when things aren't needed immediately. BUT there are times when immediate answers are needed, and the fact that this breaks someone's concentration is less important than keeping the team working smoothly.