Don't forget the bleak subtext of all this.
All these engineers working 70 hour weeks for world class sociopaths in some sort of fucked up space race to create a technology that is supposed to make all of them unemployed.
They are paid exceptionally well though. Way above market rate for their skill set was at any point in history. Work long hours for a few years and enjoy freedom for the rest of your life. That's a deal a lot of people would take. No need to feel sorry for the ones in position to actually get the choice.
These engineers make enough money to comfortably retire by the time they are replaced with AI.