This echoed so much what my girlfriend is experiencing at Amazon (London) that it is scary. She was not put on pip but one of her co-worker was last week. According to her the guy is competent and hard working.

Everything about the toxic culture, the (unpaid) on call every 4 weeks, management doesn't care about estimations they just set you impossible deadlines, lots of turnover in the team, custom, unstable not documented tools, the "customer first" narrative to make you work overtime and feel guilty. I hear about this everyday. Even me not working at Amazon I have sev2 PTSD.