I haven't seen full height cubicles since my 2006-2011 job.
Still even half-height cubicle desks tended to give you a good sense of "your space" relative to the open concept rows of tables/flat desks.
Currently I go to the office once a week, where I sit at a tiny mobile desk pressed against the side of someone else's cubicle. I'm almost "in" a walkway. Can't imagine how that interferes with focus!