So I have read in posts and in literature (Frank Harrel - Regression Modeling Strategies fx) that depending on what you do, ROC curves and AUC values are not always relevant, but often written in papers or reports anyways, and sometimes as the "ground truth" to how good a model actually is. My problem is that I'm not entirely sure I understand why it's not always a good thing? I mean, if I have a model (based on binary outcomes fx) that predicts some value for some input parameters in the model, I would think it made much sense that the highest predicted values should "align" with the outcomes, i.e. a high AUC value if it does indeed predict well. That makes sense to me. But maybe I have misunderstood/overlooked something?