Yes their libraries are their most valuable asset. They also collect benchmarking data across companies to help you gauge how you are doing. You cannot ask aws about their practices but you can ask McKinsey about the market leader benchmark practices
AWS is probably guarding their IP, there is a chance McKinsey is just making things up, you can't verify it.
The way that it works is that if you want access to the benchmarks you need to provide your data.
But in general there is no way to verify whether the consulting company is lying or not. They have been caught pants down multiple times recently.