This is interesting and it makes me really want to see the 5 4000+ puzzles...
For example https://www.chess.com/puzzles/problem/568140 is mostly rated 4000 because ...Qe1+ is so compelling that it pulls in even excellent players, while there's an easy material pickup on the board.
But there are exceptional puzzles throughout the 3000s, like 3500-rated https://www.chess.com/puzzles/problem/769056 , which absolutely anyone can follow, but few can solve on the first try.