I think it's a last resort for someone who isn't listening to a specific feedback well, it requires the manager (IME) to be crystal clear on what's not working well, and how they can improve it. And to follow up on in some cadence (every 3 days) with notes, laser focused. Giving an amount of time for the person to show they can and want to change.

In one of the cases the person who got pip'd got promoted to Staff Eng from Senior within a year, it was mostly about his attitude, not about his technical skills, and he changed completely. I think that person was just not self aware how people didn't enjoy working with him, even if the manager gave feedback, he thought it was funny or something like that.

It was a real "Am I the bad one" moment when the PIP process started. Another one was about how they always went too deep into rabbit holes and never delivered any value, to change the way they approach problems, etc.

I feel feedback from managers is extra challenging in remote environments OR in places where a person has been for too long and is too used to the status quo, and PIPs can help there.

I count myself luck that I haven't worked in companies where PIPs were used as a tool to layoff or fire people, but I also take some of those reports with a grain of salt.