it is not so simple to regurgitate pre-learned answers when you alter a problem one small attribute at a time, in each case a different answer becomes optimal, thus you can see if the person understand what needs to be done or not
i feel very strongly this is a disingenuous claim. clinical psychologists go to school for a long time to learn how to assess people's abilities to think. why should i believe that you a random software engineer have any competency whatsoever. in reality this is exactly the reason standardized exams (or standardized interviews such as leetcode style problems) exist - because average person can't accurately make that call.
Upon completion of the interview the problem would indeed look like the result of the leetcode problem. However the take away from the op is in how the question has a narrative. It enables a dialogue over time. Each sub problem provides n ways of exploring a solution. Each problem providing a sounding board for the candidate to pronounce their thoughts. Such questions are effective at providing more signal(read as talking out loud) from candidates.
it is not so simple to regurgitate pre-learned answers when you alter a problem one small attribute at a time, in each case a different answer becomes optimal, thus you can see if the person understand what needs to be done or not