>Which is why all the LeetCode interviews always struck me as odd. They focus on algorithms, not data structures,
The typical leetcode questions also focus on "data structures" because the candidate needs to have the mental catalog of data structures in his brain to pull from when he "pattern matches" on the problem/solution.
The interviewer isn't going to volunteer whether the candidate needs a "priority queue", or "adjacency matrix", or "trie", etc to solve various algorithm questions. If the candidate is stuck, then the interviewer might give a hint to the data structure to use. But of course, too much hand-holding will not make the candidate come across as a strong hire signal.