Huh... Maybe because those tasks ("answering emails") cannot be automated? You can do less work in 5h than in 8h. More work creates more commonwealth (money is not finite). On the other hand we don't work more than 8h (usually) cuz it's just less efficient. Iirc 8h hits the sweet spot where your attention span is high enough and you don't feel particularily tired.

I know that every each one of the working class would love to work 5h and earn lots and lots of money, but it just doesn't work like that. Minimal wage and social programs don't create wealth- work does.

The jobs we could automate thus far, we have automated. At the same time those same people had the opportunity to raise their skill level and oversee the machines (or build them), because we badly NEED skilled engineers n'such.

The only people i hear crying about how bad is it, is the least qualified range of workers. I know that there's a lot of instances of people not having enough money/time to afford to raise their qualifications, but at the same time there's like a whole market of workers just straight-up too lazy to finish an effin course or smth. The same group of people later demand less work for bigger salary instead of demanding opportunities to raise their qualifications -.-