I think what matters more than the abstract class vs if statement dichotomy, is how well something maps the problem domain/data structures and flows.

Sure maybe its fast to write that simple if statement, but if it doesn't capture the deeper problem you'll just keep running head first into edge cases - whereas if you're modelling the problem in a good way it comes as a natural extension/interaction in the code with very little tweaking _and_ it covers all edge cases in a clean way.