I started two trading businesses in open offices.  We spent more money to be open as we needed more meeting space for people who needed privacy and for one on one meetings.  Everyone  gt the same nice and ergonomic desk and chair. Everyone sat in groups of 4 to 8. Everyone had a view.  Everyone got free soft drinks and coffee or filtered water. everyone could leave to get a coffee too.  Hours were not tracked either.  Birthdays and milestones were celebrated. I sincerely believe that these groups were among the most innovative and collaborative in Canada.  We were a global player an exporter in an otherwise dingy and dull local industry.

Some may have open offices because they want to save money.  But the best open offices are to help build strong and flat cultures where great things can happen.

I suspect the start ups that you deride are hoping to follow the latter path as so many of their famous fore-bearers have done.