I see your point. My points are that if one really wants to show respect then (a) don't waste people's time and (b) give them a respectable severance. If you can do (a) and (b) via a PIP process, then that's cool.

Interviewing fulltime vs potential feedback? Notice pay is different from severance.

1. They might be a good worker, but a bad fit for their role. That’s as much on the hiring manager as the employee.

2. People, even lousy workers, talk. Treating people with respect on their way out may decrease the person’s negativity/bitterness. Consider it a marketing expense.

3. Severance packages come with legal releases attached, at least in the US. Less risk of lawsuits, frivolous or otherwise.

To compensate the employee for the mistake the company made in hiring them.

The longer the years of service the longer the successful track record. If you work 25 years somewhere for those years your employer was happy with you. A new manager / business downturn / new system / new disability / personal prompting a poor performance means the employer must support the employee and that can become severance.

The length of employment is the most important part of the equation.