Dan Abramov came up with smart/dumb components to work around the fact that React only had components. He needed to put logic somewhere, so he thought of smart components. The whole idea is not even current in React anymore, since hooks have all but replaced smart components.

Angular has always had a place for logic: services. The concept of smart components isn’t needed in Angular. Never was.

A more appropriate separation is generic UI components vs. business-aware components. For instance, a toggle is a generic UI component – it could be part of any app and is not aware of what your app is about. A todo list is a business-aware component – it knows that your apps is about todos.

I suggest all your generic UI components should rely on Inputs and Outputs. And all your business-aware components should inject services. So your todo list component should not receive the todos through Input. It should retrieve it from a service. Even if all it does is to render the list.