Why don't we do online learning? Each failure is a new training sample. Why dont't we do active learning? Or adversarial networks, or.... Sure it is easy to f

Why don't we do online learning? Each failure is a new training sample. Why dont't we do active learning? Or adversarial networks, or.... Sure it is easy to fail in machine learning. But it doesn't mean that we need to undstand how and what our models learn. That's the only big advantage of machine learning: the model learns, so I don't have to.