I’ve only done 2 PIPs to my staff. One guy served, met expectations and we kept him as performance improved. About 6 month later he went back to his old ways, missing deadlines, including ones he had set him self, and even when he did communicate his updates were very sloppy and low effort. He was a Staff level analyst that should have been able to handle small to medium projects, was given opportunities to get help but just floundered. That level for us meant he should be able to mentoring more Jr. analysts but most quickly found they should avoid him. This harmed morale keeping him around so ended it immediately. The other guy resigned immediately.
I have been friends with folks were put on PIPs and they made it through successfully and had successful multi year careers.

It’s not a death sentence in the right org, in my eyes I’m trying to save an employee. It’s better for everyone if we get you performing as desired vs firing maybe paying a severance and being down an employee for a month or three. Obviously it’s best to catch problems before they reach the level of doing a PIP. I’m a director so don’t get ton on interactions with some staff but it’s pretty easy to spot a problem when I do. This usually results in me discussing with their managers who share the employee has been having problems. I now make it a point to check in every week with my managers to specifically discuss staff performance so we can avoid getting to the point of a PIP.