Amazon will PIP that one person.

Amazon isn't Google, it doesn't care about its image, like ... at all.

Can't PIP everyone.

Most companies I've worked at had a large majority of people adding as little value as possible.

Amazon: Hold my beer...

I'd say Google also doesn't care. Googleyness is gone, top-notch job security is gone, leadership doesn't listen to employees at all, the only thing that matters now is appeasing stakeholders.

With how Amazon's performance reviews go, which are seriously two questions ("what's your/their superpower" and "what could you/they improve") and an aggregate from your manager, nobody will notice.

amazon seems much better at managing out poor performers . what gives?

...and hope that they will not notice the former?