In my experience consulting in boring offices of companies that provide business reporting and compliance services a lot of the people only have a few hours of work to do most of the time. But a lot of the processes are manual and brittle and so every so often there is a crisis and if they didn't have everyone to minimize the impact of the crisis on their customers they would lose business fast.

I bet there are a lot of companies where productivity is low because people don't make extra work for themselves, do what they need to meet low expectations but the company needs to keep people around because they can't build processes that don't need the people.