Why time sheets kill productivity

Organisations have time sheets for their employees to fill.
Which every employee fills with productivity hours.
Not realising, it indeed hampers their productivity.

This is how it works: If an employee works for 8 hours and another one for 5 hours, the first one is more productive.

Except that its not true.

What if the second employee took 30 minutes to nap?
Or went for a walk for an hour that indeed multiplied her productivity?
Or perhaps went to the office balcony and stared at the nature for a few minutes, which indeed let her look at an error that the “8-hour-productive employee” failed to look at?

We all function at different levels of efficiency. But most people term people just as “productive” or “unproductive” on a system that silently makes the productive one also unproductive. Because she cannot do all of that and has to be at work for 8 hours, she will lose her interest, curiosity, and of course, productivity.

The last thing we signed up for, while creating timesheet productivity!