Source - worked for a startup that was acquired by Amazon. My team was slowly managed out of the company and replaced by teams in Seattle. Most of my team was let go by PIP, essentially claiming we weren't "performing at a high enough standard" since they weren't willing to reprehend my boss for being incompetent.
However, I'm proud of the fact that in my exit interview my incompetent boss tried to have me give a "reason for my willful exit" to which I responded "oranges". I mostly did this because there was an Amazon HR person on Chime (internal Amazon Skype) during the meeting recording a transcript of the meeting. So at some point, my boss had to explain to her boss why she fired someone and explain why my reason was "oranges".
TLDR: Amazon is cheap, doesn't care about workers and is kind of horrible.