I certainly see your point; helpful/harmful is just hiding the ball. Helpful to who or what? Harmful to who or what? Instead of finding "good" we would find "good for so and so"; in which case "good" would be synonymous with "furthering some end". But furthering some end is also what evil does; evil just furthers the other end. So, in helpful/harmful there would be no way to distinguish between good and evil.
Maybe a "god-based morality" would be the determination of the strongest. However, it would depend on who the god is.
Is the god just a powerful being who has a strong desire for some outcome? Then "good" would be what the more powerful being wants, e.g. War or Sex etc.
Or is the god, God, that is to say the source of being and being itself? Then good would lose its quotations because the source of being is capable of providing an objective measure of what is good.