I literally just got let go from AWS two years ago in the midst of hundreds of layoffs. Absolutely no one cared why I wasn’t there anymore or even asked. I had four interviews and three offers within two weeks.

Even more relevant, one of my former coworkers at AWS who was now a director at a well known public non tech company knew I was going through the focus -> PIP process and encouraged me to stay until I made it through my next vest, got offered severance and said call him when it happens and if I’m interested he will either make a permanent position for me if possible or at least give me a very lucrative contract. He didn’t even care and he knew I was getting PIPd

I'm glad that worked out for you. In this other case, a company publicly announced that people were being fired for low performance.

Even if the colleagues of a given person knew/suspected that the person was a good worker, everyone else hiring at other companies doesn't, and they heard what the last employer said.