Yes, things like Google Search must be increasing productivity. But at the same time the amount of time dedicated to infotech entertainment addiction is going through the roof. I wonder how much productivity the hours of Facebooking at work is costing us.
Forgetting for a while the non-linear costs of distraction in cognitively intensive jobs, I wonder if Facebooking at work is really costing us anything at all? I'm having a hard time imagining that office workers of 20+ years ago were that more job-focused than they're now. But then again, the problem may be Internet in general - I can't imagine people being able to do so many non-work errands while in the office if…
When people wanted to zone out they read books, usually. Audiobooks were also common. I brought the entire series of Discworld novels in on pdf, and managed to read the entire series while I worked there. I also wrote a bunch of notes down on paper.
Hell, when I was working in warehouses away from computers entirely I'd still zone out during it and mentally work out some ideas for personal projects once I was done with work. Sometimes I actually miss that, since I seemed to have a lot more ideas then.
Point being, you don't need computers or internet for people to find ways not to be 100% productivity machines.