Learning to mate involves determining how "trapped" the King is, and examining how to control the trap (protect the attacking pieces, controlling escape hatches

Learning to mate involves determining how "trapped" the King is, and examining how to control the trap (protect the attacking pieces, controlling escape hatches, watch for in-between moves and checks from the opponent, etc.). But after Rf4, the King is has no moves, attacking pieces are protected and Black is not vulnerable to checks. All you need is a piece that attacks black squares, and the Bishop move becomes obvious. This problem more shows most players don't use a disciplined assessment method in tactical situations, but quickly generate move trees and obvious tactical themes, then start combining themes and moves. GMs were famously shown to spend much more time on assessment than on move trees than top club players. Yes, much weaker players analyzed more...but assessed less.