When you pay someone and you control both their place and time for over 1/3 of their daily life, there are inherent problems. I'm not sure that any office plan is ever going to be super ideal because of the fundamental problems of power and control that come with an employer/employee relationship.
Open plans are designed to look cool and help recruiting. They also create a sense of "busyness" that owners and managers love. Busyness is proof they are still in charge.
Arguing about wether or not it is better for productivity is a red herring. It was never about productivity in the first place. Most of what happens in an office is only tangentially related to the idea of work efficiency.