You're lucky. A PIP is basically HR creating a paper trail to justify your eventual termination (in case of lawsuits, etc).
This advice is more valid in our current, exceedingly tight, labor market and less so when unemployment goes up again (be prepared for a longer search, network more aggressively, and have a longer emergency fund runway).
ie. it's likely we believe the odds to be low, because it's not something people talk about.