Yeah I completely understand. One thing I think has to be kept in mind that Asana is no time tracking tool per se. Meaning Asana would not know how much time somebody working unless it can pull the info from somewhere, which would be custom fields in this case or the total tasks which makes the whole thing more complex.
Hence why Asana evenly splits the hours based on the days.
I get your point if let‘s say somebody has 3 tasks assigned in a week
Task A: 8 hours
Task B: 12 hours
Task C: 20 hours
They are all assigned to go across Mo-Fr.
Now this person might work 8 hours on Task C on Monday but no work is done on the other tasks. So it would kind of not be as correct based on the workload either. Except for that for the planned time range the schedule was planned and the coordinator knows this person is full with tasks.
Now from my end I can see that we use the Workload feature mainly when we have a new project that is planned out to prepare on overview. But we also work with custom fields as explained above already as Asana needs to be able to pull the input data from somewhere. Especially for big tasks that is crucial.
In general however we try to avoid big tasks and rather split things up more into columns + we use milestones and goals.
Since we have the custom fields added for allocated time, consumed time, allocated costs (for expenses such as when we work on client delivery tasks), consumed costs and more, we work with list view there as well a lot as there we can see the summary nicely as well.
Some open feedback request topics you might be interested in upvoting: