Allah Erased Memory Of Ahd-e-Alast Doesn't Make Sense
I agree with your point that this scheme of test does help a human get the best out of him in both worldly and religious spheres. The extensiveness of the test is not constant for every human being i.e. it is not a static test. The premise remains the same that it’s a two-fold test, but how those dimensions unfold for a human being and how deep the test goes changes from situation to situation. In the absence of a Prophet, the realization of a creator and good deeds ( universal ethics ) would suffice for one’s success. But with the introduction of prophethood, now the test becomes deeper, as there’s sharia to be followed as well and knowledge becomes more clear as to who is God and what God wants and about the day of judgement etc etc.