Many have thought and still think that multitasking and quick things are productive, I see the exact opposite. And we can see it at another level in mean per capita hourly productivity: in the past (so before business model substantially merge around the world) French hourly productivity was the highest in the world, and they are still one of the less-working in term of hours and holidays. USA, Japan and Germany are the opposite, they work far more and have a far lower hourly productivity. To the over extreme try the difference between a lover vs a prostitute...
Open spaces are another TOTALLY unproductive things, born only to push more economic constructions sold as a higher price and facilitate reorganization. The letter also is one of the less productive thing we have if done constantly because any change, if positive, demand time to start pay back, doing constantly means NEVER get paid back, only suffer the change itself.
Not at all. Voice chat is synchronous - you must stop whatever you're doing and listen or talk in real time. And people nearby will overhear.
Chat is asynchronous and private. I can chat and consult a colleague while I'm in a meeting with a client. I can keep a chat open while coding and read/respond when I'm not most concentrated. I can go offline and answer a question the next day.
Text chat isn't literally "chatting through text". It's email with a different UX, more suited for quick communication.