[apabepa]

I recall hearing/reading that a lot of the time in the office is passive/suboptimal. The productivity gain is that you have the people there in standby. The gain is that the important work that do happen is not blocked by people being off work since you can pull them in instantly compared to "Only Bob knows X and he left for the day, lets schedule a meeting tomorrow"

[TheOperator]

Or you could just schedule people to arrive at the same time but have them work shorter hours.

[TomMarius]

That would cause an impossibly tight schedule for everyone and no actual work would have time to happen

The way I see it is: Bursts of work combined with prolonged pauses because of others' schedules and other issues with coordination

[JohnFen]

Or stagger shifts so that there's always someone at the ready.