It's such an unimaginative metric. First, we lump all jobs together into one bag. Depending on who you are some jobs are an actual joy whole others are absurdly demanding. We have zero dialog about the correct number of hours for each.

Lots of jobs (both physically and mentally) require slacking off half the shift. I've seen quite a few that on paper require 8 hours of top tier athletic performance. It might be possible to train a person to accomplish that. The work schedule looks nothing like a training program.

To grow, mental and physical challenges have to push people to their limit for X hours over Y days where X and Y depend a lot on what it is one does and their point of exhaustion. If you are not exhausted you aren't growing. When you are exhausted you should be resting. Rest should be exactly the right duration.

If people are never challenged physically, mentally (and perhaps socially) they will decline and eventually the lack of physical fitness will eat away their mental performance just like a lack of mental challenge will ruin physical performance.

There is no discussion about the duration or frequency of shifts.

If you look at it strictly from a greed and exploitation perspective it is a dumb idea to pay someone for 8 hours if it isn't possible to do more than 5 hours of work. It is dumb to have people work 5 days if they are used up after 3. It is dumb to have 2 days of weekend if the employee is not recharged. The collective goal was to exploit them until retirement. If they cant even be allowed to grow stronger it is a truly dumb schedule.

I had a job once that involved a weekly truck full of 75 kg bags of flour. About 10 employees were unable to do a single bag, about 10 could do 1-5. Then there was one guy who did the other 150 bags. Not a coincidence it was the same guy who put them in the mixer. Say 10 000 kg. The world record most weight lifted in a day is half a million kg or say 6500 bags.

They calculated top memory sports people are on average 5000 times better at remembering things than untrained people. They weren't born like that nor did it just happen suddenly.

Lots of people want to start their own business but they are terrified by the amount of work and level of uncertainty. It doesn't seem like we want people to start their own business. We need them to but it looks more like we've made it intentionally complicated. Complicated enough that you probably shouldn't invest in them.

There is also the angle of people able to support you. If everyone has 4 day weekends you really should ask them to help you. If it is only 2 days you'd best not bother.