[TheOtherHobbes]

There's a common trope about an established worker who works really, really hard at tasks - evenings, weekends, the whole deal.

Then they retire. Someone else takes over, and they do exactly the same work in $small_percentage of the time.

So no - effort is not a good metric. Why would you be paying someone who can't do the job - or at least can't do the job well, with enough spare capacity to deal with more complex work requirements?

Of course this is a parable, but I suspect a lot of people have seen something similar happen at work at least once.