Probably also there.. does this contradict anything I said?

That just means that doing more hours won't help more.. where ever you are (there are always exceptions).

I would say equal amount of time is being wasted even if you work less hours but public sector tolerates less being done. For example your morning windup routine is the same, your lunch takes the same time, you need to go to bathroom, pointless meetings are still there - I don't really see what would improve about my productivity if I worked less hours - what would I be able to eliminate in order to shorten my time at work ?

Even if time is "wasted" with breaks at work this time is between events - not at the end of the day - and I usually don't have the ability to compress it.

And also the economics of working more hours once you become a critical contributor are very different from a person staying in late for appearances - adding a person to take over the load has multiple costs - hiring risk, training and on-boarding time, extra sync and communication slowing things down.

I see. I don't have experience with the public sector myself but what I meant is this:

If I have only a 4 hour workday, people(bosses) think twice about wasting my time with useless meetings. Also it gives me energy to start into a day with only 4 or 5 hours ahead instead of 8h+.

Of course having a shorter workday doesn't make it 100% productive. But my personal experience is that it is MORE productive. Sadly most of my days are 8h+.

I also want to add that a tired, worn out developer might even cost productivity by introducing flawed code into the codebase. Did you ever do a serious code review while being tired? I don't see how that works. Then others have to deal with all this stuff afterwards.