Scala Design Patterns - Second Edition

What it is not so good for

We have covered the positive aspects of using decorators; however, we should point out that overusing decorators could cause issues as well. We might end up with a high number of small classes and they could make our libraries much harder to use and more demanding in terms of requiring more domain knowledge. They also complicate the instantiation process, which would require other (creational) design patterns, for example, factories or builders.