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

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.