It doesn't have to be an office per person. Small groups up to 8 people can work well and very doable without a big loss in usable square feet.
I suspect most companies that absolutely need every inch of continuous desk space have bigger problems. Organic growth isn't difficult to manage, it's the crazy VC fueled hiring sprees that create real estate issues.
What downsides of a large open office are eliminated with an 8-person room? 8 seems like a lot of people if you really want the peace and quiet of an isolated office, and it doesn’t seem like a 50-person open office is going to be much louder or worse than an 8-person office.
Sound levels rise with the size of the crowd. More people making noise, more conversations more of the time, more space to spread the sound, and less individual accountability means people talk louder to be heard and are less considerate of their neighbors, creating a feedback cycle that ends up in a very rough environment.
I don't know how true this is for others, but on-task discussion doesn't grate on my nerves like random off topic conversations. If someone is talking about some aspect of the project I am working on right next to me, I can handle that MUCH better than someone in another department 4 cubes away bloviating about what their kid wore to prom or who the Piggers beat the previous night ("YOU SHOULDA SEEN IT MAN!!").
I know that isn't the case for everybody, but I think I'd be quite comfortable in an 8 person war room as long as folks were actually working on stuff.
I suspect most companies that absolutely need every inch of continuous desk space have bigger problems. Organic growth isn't difficult to manage, it's the crazy VC fueled hiring sprees that create real estate issues.