My own experience is that hours worked are irrelevant. It can vary. Deal with it. To believe otherwise is to think management fully understands the work ahead of time. This is not usually the case. To a lesser extent, even the devs might not know. Overscheduling and underscheduling happen all the time. Things catch on fire. You have to work accordingly. Some days you can stop early. It's not entirely in the hands of the workers. You won't know until you start.

What matters more is a reliable result done on time and everyone is happy with the effort required to achieve that. That's a complex balance to achieve across the whole team. You need everyone recognizing the long term benefits of a job well done and they need to feel comfortable with their part of it.

Working slowly after hours with no promise of getting much if anything concrete done is a deep joy for some of us. I sometimes need to play with my work to know what I'm doing tomorrow. It's often outside the scope of what I'm being asked to do, yet vital to a successful project instead of a mediocre one full of garbage decisions smoothed over by management lies and stress on the whole team to maintain.

What world does one want to live in? Build it and enjoy. That's where productivity, happiness, and ease come from. There are so many heroes out there casually looking at work while eating cereal in their underwear at 1am. They're no more stressed than anyone else.