There are many conclusions to be drawn from the previous implementation. While it might seem like a good approach, there are cons that come with the benefits; after all, no architecture or implementation is perfect. This means that a solution such as this one cannot be good for all cases, so it will pretty much depend on the circumstances of the project, the team, the organization, and more.
While it's true that the main idea of the solution is to abstract details as much as possible, as we shall see some parts cannot be fully abstracted away, and also the contracts between the layers imply an abstraction leak.
