Traditional pipelines are rebuilt for each task
Because the features are chosen by a person for a specific problem, a new problem means a new set of features. A spam filter, a credit model, and an image classifier each require their own design effort, and the work does not carry over from one to the next.
Deep learning reuses one recipe across task types
A deep model is not tied to one kind of feature, because it learns its representations rather than receiving them. The same basic recipe — a stack of layers trained on examples — applies to images, audio, text, and sequences. What changes between tasks is mostly the shape of the input and the shape of the output, not the underlying approach.
Transfer learning as flexibility in practice
A model trained on a very large image collection learns general visual structure along the way. That trained model can be reused for a related task, such as telling two similar product categories apart, with far fewer labeled examples than training from scratch would need. The earlier learning carries over. A traditional pipeline has no equivalent, because its features were built for the original task and do not move to a new one.
Flexibility is the same property that costs
The flexibility that lets one model family cover many tasks is the same property that produces the data hunger and the compute bill discussed earlier. Learning representations instead of receiving them is what buys the range, and it is also what requires many examples and heavy computation.