They specifically mention "the P team at AWS". The two following things are perfectly able to be simultaneously true:

* The average Amazon engineer is not expected to have awareness of CS fundamentals that go beyond LeetCode-y challenges

* The average Amazon engineer builds using tools which are each developed by a small core team who _are_ expected to know those fundamentals, and who package up those concepts to be usefully usable without full understanding

(I did 10 years on CDO, and my experience matches yours when interacting with my peers, but every time I interacted with the actual Builder Tools teams I was very aware that lived in different worlds)