It sounds like you might need a jade egg.

The 7.5 hour work day. The mutual help culture (no question-shaming) and friendly colleagues. The physical environment (a nice old industrial building with exposed brick - I just can't with the all-white synthetic).

Given the choice, I wouldn't work where half my team is not physically around. I just find half-empty offices distractingly depressing.

Check out https://www.salon.com/2012/03/14/bring_back_the_40_hour_work_week/ Mind work has been shown to decrease in quality after 5 hours a day.

When I was a grad student, I'd work until I couldn't anymore, and that was 5 hours a day. It got me a Ph.D. in Physics.

8 hours is too much. The military shouldn't be taken as a reference. Unless you aim to destroy everyone's mental health.

As a developer, going from 8 to 7.5 (current job) made a huge difference. That extra 30 minutes I'd always run on empty and I'd grow increasingly snappy at my loved one. I will not go back to 8 hours a day if I can help it. Never again. My mental health is worth more than this.