Sure, I work at Amazon. Amazon's HR principles get vilified in the press. I'm not going to claim they are all perfect, but most of these principles presents a position on an interesting tradeoff. Let's focus on the unregretted attrition (URA) notion. Isn't firing 5% a year really high? What about teams of top performers?
I promise if you look around at a team of 20 people, there's a high chance one of them is not very good. If you DON'T have a URA target in place, managers may let these low performers stay, especially since firing people is actually quite difficult. This leads to what Bezos would call "Day 2" culture. It's hard to overstate how much damage a single person can cause to a team's output or morale.
If you look at Amazon's implementation, it's really not that bad. If you have a superstar team of 10 people under one manager, great, the 5% is resolved at the 50-100 person level, so make a case and keep your team. Or even better, hire some junior engineers so your superstars can lead and teach others. Some of those junior engineers will be bad; others will be great. This isn't hire to fire, rather, hiring is noisy. What if the whole 50 person org is amazing? Umm, this is just statistically unlikely. Everybody I've personally noticed leave after PIP has been, in my estimation, a poor performer.
Amazon has one single HR policy that is amazing: you can change teams any time for any reason (unless you're on a performance plan). If your team sucks, get out! I've been able to land on teams with good WLB, smart coworkers, and fun, interesting, meaningful projects -- except for my first team, which I left after 2 months.
Lastly, of course there are tons of anecdotal stories from people with miserable experiences at Amazon. Can we at least accept Amazon is a massive employer, and these are bound to happen?