This is true for most employers in the US. Nevertheless, most employers would rather help an employee (especially one whose situation is temporary) to succeed,

This is true for most employers in the US. Nevertheless, most employers would rather help an employee (especially one whose situation is temporary) to succeed, because hiring and onboarding is way more effort than getting a previously good employee back to where they can perform well again. But, once a point of no return has definitively been reached, I think it’s best for both sides to not drag out the separation with a checkbox PIP or other theatrics. Pay the employee a reasonable severance and separate quickly. (I’ve seen genuine PIPs succeed and result in long-term continued employment; theatrical, check-the-box for legal/HR PIPs are cruel and wasteful.)