Some of the best people I know that have gone to work there have been subjected to this.
After cycles of this, the only way to survive is to backstab and move up in management.
Amazon/AWS really shows this in it's core web sites and console, which are really backwards and show no signs of improvement or evolution, because all the people that built it have been fired by now or moved on.
Microsoft originally thrived on this, but eventually the culture collapses into backstabbing and the worst breed of middle management Machiavellis, and any productivity is new bolt-on products.
So IMO Bezos built a fundamentally good infrastructure ten years ago that is fuelling Amazon's continued growth, but if anyone fundamentally improves in some way that Amazon would need to fundamentally change the company it will be impossible.