Very much this. Leetcode is terrible, but the checklist of trivia suggested in the essay is equally terrible, because it's too easy for a genuinely good program

Very much this. Leetcode is terrible, but the checklist of trivia suggested in the essay is equally terrible, because it's too easy for a genuinely good programmer to simply not have experience with topic X. Or, for more experienced candidates, to not have dealt with that topic for several years and not have the knowledge fresh.