When we are young and inexperienced, we tend to think that if we work harder we will be more productive.
As we gain experience (and age), we start to realise that this is not true. Too much of our effort is unproductive. We slowly learn to work smarter, to prioritise, to eliminate waste, to think our way to a better solution.
As a manager or leader, you must remember these things. Do not keep exhorting your troops to work longer hours or work harder. It is your job to find (and fund) the smarter ways of working, to eliminate tasks that are not productive, to eliminate distractions and to motivate behaviours that move things forward.
This is not always easy … but you fail if you don’t try.