There are different kinds of "work" and generalizing to one set schedule isn't going to work for everyone.
A retail clerk can likely do a 10 hour shift with little to no loss of productivity in the later hours - and some jobs basically just need a human there to monitor the process - those likely would do well on 4/10 shifts.
But other kinds of work can't get much beyond six hours a day anyway, in which case spreading it out may make sense.
But there's also a weird "fairness" aspect - even if everyone would be better off with varying schedules, people would think it "unfair" - and it's visible. If Sally gets paid half what you do, you never know. But if she leaves after 4 hours each day, you start to feel annoyed.
A retail clerk can likely do a 10 hour shift with little to no loss of productivity in the later hours - and some jobs basically just need a human there to monitor the process - those likely would do well on 4/10 shifts.
But other kinds of work can't get much beyond six hours a day anyway, in which case spreading it out may make sense.
But there's also a weird "fairness" aspect - even if everyone would be better off with varying schedules, people would think it "unfair" - and it's visible. If Sally gets paid half what you do, you never know. But if she leaves after 4 hours each day, you start to feel annoyed.