You can definitely argue it's not fair to pay somebody extra for not doing a job but the alternative seems to be you keep paying them even more to keep not doing a job (and possibly doing negative work).

Rather than put somebody on a pip for x months just offer them x months of salary to quit. Same money, same work done.

There's a legal distinction which impacts whether or not the employee is eligible for unemployment benefits, among other things.

(although legally "firing" vs "layoff" is irrelevant, depending on the situation you can get benefits despite being what a layperson considered quitting [1]).

[1]: https://www.darwingray.com/from-desk-to-departure-when-movin...

The company could be sued by a non employee too. What difference does that make?

And if your company procedure requires a PIP, then you do that. Again, where's the difficulty?

Nothing you've said sounds difficult in the slightest. It's following procedure.

It’s difficult to stop lying sometimes