[austincheney]

There are legal reasons why that does not work. For example consider military separation. A candidate is under no obligation to disclose their military/veteran status. If that candidate then becomes mobilized the federal obligation trumps the commercial obligation. Employee leaves and not only are they separated from the work without any repercussion the employer is required to retain that employee in an unpaid status for at least 5 years unless a rare legal exclusion is met.

There is also pregnancy. An employer cannot terminal an employee for taking time to give birth and taking some more time off immediately after.

These are the two most obvious reasons though I am sure there are many more that they cannot enforce.