I don't really agree, the difference between being alone in my home vs being in a office with a few people makes me more productive at home. If you're offering personal offices to people that can't have an office at home though, I understand why you would see people more focused at work.
> Sure, now that we have reached to this point, some people can work at home. But the sustained work is done with your colleagues beside you.
Not sure what you mean by "the sustained work". Sure, work was harder when I worked at McDonald's compared to now that I work in software, but on the other hand software gives me way more leverage with what I do, and so I can produce more value. I'm not saying that I'm changing the world here, but I can write a small script in an hour that makes some manual work for a few people automatic, and thus improve their productivity. There's no way I could do something with an impact this big at McDonald's.
> The internet. The vast, vast majority of companies that are the backbone of any country. The financial system that runs credit and capitalism. All these things were built in the office or it's equivalent.
For the internet at least, most people involved had personal offices. Mixing personal offices and open spaces is, I think, a big mistakes. Most employers only gives open spaces, which don't allow to concentrate on work as much as you would like to. I do agree that personal offices with nice shared spaces are an ideal for work. Anecdotally, most research lab that I've seen followed this pattern.