I too was put on a PIP early in my career, and worked my way out of it. It was fine.

That said, I agree with the general sentiment that much more often than not the employer is not acting in good faith. Over the decades I've seen way too many colleagues get put on a PIP, I tell them to work hard because it can get better, and then they get let go anyways.

Not sure what I'd do today if it happened to me. Probably a bit of both. Take it for the feedback that it is & try to improve my flaws. And also start looking around for a new employer, knowing the reality of the situation.

PIP and similar things also get "misused" with other anti-management techniques like stack ranking.

Someone I know got put on a PIP solely because the dictates from Upper Management said that annual review scores must have a certain distribution and average per team - and that naturally means someone it at the bottom. And the dictated numbers means that people with lower scores must be put on a PIP. It happened to be the newest, least experienced member of our team, and the PIP "plan" itself (as written by the team lead) was effectively "Continue what you're doing", but they were still forced by HR to do it.

They left themselves a year later, and I don't blame them. They just re-introduced all the worst parts of "stack ranking" and firing the "worst" person in the team with more bureaucracy.

Worked as a PM at a well known tech company, great relationship with my director. He leaves, new director comes in and within three months I'm on a PIP. I'm given a list of work products to create for a new offering that has been discussed, which on the face of it are entirely reasonable, and the standard 30 days.

100% ghosted by my Director. Weekly 1:1s? He no-shows 2 of them. Near zero input. In "fairness", I knew what was happening, but had some tiny semblance of good faith. Hah.

Final meeting, he shows up with HR. "So we've been talking about (when?) and I have just completed my final review of the documents you created (bear in mind these have had significant input from multiple stakeholders who, not for nothing, generally approved), and I am still left believing that your output is not up to the quality or depth that we expect from our PMs, so..."

I pulled up the receipts, because why not? I think he may not even have known that GDocs provides good metrics on documents, including who has viewed, and when, and how many times. I did this with the HR person sitting awkwardly there. "You reviewed this document? GDocs says you've never accessed it. And this one? Never accessed. What about this deck? Never accessed."

At that point he turned his cam off and clumsily handed it over to the HR person. They asked if I'd like to follow up, but that the company would support the Director's decision. Fine, didn't expect any different. They did acknowledge that they could see too that he hadn't done anything to even present a token perspective that the PIP was anything other than firing with 30 days notice.

Lives and learns, we do.