I have read somewhere that there is often _less_ face-to-face communication in an open landscape than with single offices. Possible reasons include an unwillingness to disturb everyone else, and that people in such situations tend to turn inward in order to isolate themselves from everything and everyone around them.

Also (and somewhat contradictory to the above), I expect that, if your colleagues are _too_ easily available, you'll be running to them with a half baked question in your head, only to blurt it out before realising you didn't think it through, and wasting both their time and your own. But before you go knocking on someone's office door to ask a question, you really want to be sure that you know what you want to ask, and that you understand the problem well enough for the answer to make sense to you. Which leads to a better conversation, less time wasted, and better learning.