It's the difference between "established company" and "startup" though, isn't it? Sure, at an established company with 50+ up to tens of thousands of employees

It's the difference between "established company" and "startup" though, isn't it? Sure, at an established company with 50+ up to tens of thousands of employees, all these nuances and efficiency-by-working-less gains come into play. But, when you are 3 people and you have to ship 6 features in the next 2 months, and each feature will require a minimum of 3,000 lines of code, and you can write 200 lines of code every 6 hours... your only option is to work faster and better and longer than any potential competition. Maybe you can pull two to two and a half 6 hour sessions every day instead of just one per day. There's always a race against the clock for runway. Most of the "great" products we see from the past were created by driven teams overworking themselves to change the world. The entire 30/40 hour stable work with vacations and breathing room and weekends off comes later in the life of a company.