20 hours a week is pretty much the ceiling in my experience beyond big crunch times, special events, etc. If people really stepped back and thought about how much time they spend screwing around at work I think they’d be surprised, like how many people were surprised to discover how many hours they spend on social media apps when screen time tracking was introduced in phones.
I worked in the film industry for several years on the Hollywood side before switching over to commercial. 12 to 14 hour workdays were pretty much the norm. When I flipped over to the more commercial side, our workdays typically ended at 8 to 10 hours. And let me tell you, the commercial productions were exponentially more efficient. We got more done per day by a large margin, no matter the scale or complexity compared to the films I worked on. When you know there is less of a threat threat of the company extending the hours, you tend to get things done in the time allotted.