Managers look to hire good employees. Good employees are people who finish their work on time. Good employees will occasionally have free time. If managers ask them to complete another task without additional pay every once and a while, then a good employee will complete that task. If a manager has 4 good employees, the manager doesn't need to hire 5 people.
What separates managers from bad managers is very simple, force. A bad manager gives an employee less time to complete a task to force employees to work faster. The “logic” behind this is that if a good employee finishes work 50% quicker than the allotted time, the employee can do 1/2 of another positions work. If you reduce the allotted time by half, then theoretically you can force a good employee to do an extra positions work. That means you only “need” 3 employees to do the work of 6. If the good employee is also a smart employee, they'll penalize the employee for working too slow.
Bad managers create burnt out employees, who do twice the work one good employee can do, then defame good employees into positions of compliance, or force them into narcotics, stimulants, and depressants; leading to the use of pharmaceuticals to reduce anxieties, and genuine human breakdowns labeled as illnesses that only exist because of a machine designed with the intent of forcing as much labor out of people as possible, while ensuring they remain completely dependent on the machine's operators.
Work isn't supposed to break people. Work is meant to be a way to supplement deficiencies in an individuals ability to maintain a homestead. Work is not supposed to be how an individual keeps their homestead.