"Private personal space + collaboration friendly areas to be available as needed" has been the recommendation of basically every study I've seen on how to maximize software developer productivity.

But bean counters kill that idea right quick.

Especially useful for phone calls -- don't need to hunt for an empty phone booth or book a room.

I used to have my own office working for an older industrial company. Now that I work for a tech company, it's all open concept. I have no problem focusing, but taking calls, especially private ones, is a pain.