The accuracy trap: Achieving high accuracy may not guarantee effective model evaluation if there is class imbalance.The precision-recall nightmare: A high precision but low recall model can lead to missing actual cases.The F1-score fallacy: Opting for a balanced F1-score may mask flaws in evaluation strategy, causing significant consequences.The dark side of model evaluation: Wrong metric choices in healthcare, finance, and e-commerce can result in costly mistakes and missed opportunities.