> However, there are lots of jobs where output really does scale linearly with input time. The obvious ones are hourly service workers in retail or restaurants, but even some 'high status' jobs really require the hours (healthcare, airlines, union manufacturing, etc...)

With manufacturing, I disagree due to the impact of automation - especially when analyzed over a long time frame, productivity has exploded whereas the number of employees has shrunk drastically and their inflation-adjusted wages barely growing.

In retail, restaurants, even in some parts of healthcare (think lab work) the situation is similar. Automation, mass manufacturing and containers (the physical things, not Docker...) have slashed costs on the input side, menial tasks like stacking shelves or cleaning got cost-cut (by outsourcing and by exploitation of undocumented workers), some places like IKEA and Amazon even eliminate the cashiers by having the customer do that themselves.

The owner class has reaped all the productivity gains and given back little to the workers who made it possible, and now they are asking "why is the American/Western market for cars shrinking and the only growth in China"... well easy, too many people don't have the cash on hand to splurge on a dozens of thousands worth new car!