When you find yourself wondering why a character in a book or on screen is taking certain action, sometimes the problem is nature.
Nature conserves energy, physical and mental. We don’t take actions which we don’t believe are the minimum conservative necessary action. Our wiring makes us look for the easy solution to whatever comes our way. And if it’s something we can ignore, inaction is the ultimate conservation. We do nothing. Lots of it.
Making our characters do something because it’s good for the story is weak writing. Readers will sense something’s amiss because they instinctively grasp nature’s imperative.
I’m highly unlikely to walk out to the frozen edge of the lake and look around, just so some storyteller can make me find a body and let them get on writing their mystery.