Manufacturing isn't like that at all. In manufacturing, if you double your inputs, you get at least twice as much stuff out, and through economies of scale, may get more. This works so well that manufacturing employment is only 7% of the US workforce, yet the US produces more stuff than ever. (Yes, even with importing a lot of stuff.) This also applies to construction, mining, and agriculture - all the real stuff.
Finance, however, isn't like that at all, because it's mostly zero-sum. Winning matters. Avoiding losing matters more. In subsystems where winning matters, there is an incentive to put excessive resources in to avoid losing. This is also true of advertising, startups in crowded fields, and businesses with high brand recognition.
The reason people in the US are working so hard is that there's no effective pushback against this in the zero-sum sectors.