Classical mechanics makes sufficiently accurate predictions to enable essentially all the engineering we do and was invented after we have been engineering things for a few millennia.
If you construct highly controlled experimental conditions predicated on classical mechanics being true, then in those scenarios, the model predicts.
But in almost all cases it fails to predict, because the situation is vastly too complex to model. You are only able to construct devices (eg., steam engines, baloons, etc.) which are "simple" in the relevant ways, because classical mechanics successfully explains real properties of objects.
If it didn't, you'd have no idea how to take an ordinary situation like, "dropping some objects off a cliff" into one where you could actually predict where they will land (ie., by waiting for a day with no wind, by shaping the objects to limit drag, and so on --- without controlling for these accidental features, you'd not be able to predict where anything would land other than "down there somewhere").
