Possibly rated so high as there seems to be multiple ways to do it. I think the required solution may still be the fastest.
Oddly the computer was claiming some of the solutions that seem to work as a draw. Don't think they repeated the position thee times or anything like that. Generally the computer realised it was mate just before mate was delivered. Of course I could be missing somthing obvious - I am no expert
I was doing puzzles when I came across this nonsense which doesn't belong in puzzles at all.
https://www.chess.com/puzzles/problem/1332795
Staff, please remove this puzzle as it is totally pointless; one should not have to calculate a forced mate in 3 in a king + rook vs. king.
For the cherry on top, this puzzle is rated 2900+ with a 25% solve rate.