Allah Erased Memory Of Ahd-e-Alast Doesn't Make Sense
Just like other creations we are here to play a role. The test is a control to motivate us to excel in our role. The test is a means to the end and not an end in itself. It’s like if I hire someone to grow my market share in US and pay salary as a compensation. My purpose of hiring would not be to pay salary but to grow business. If God wanted to make the test harder for us He would never have sent so many prophets and books. So if the memory could have helped us do better in our test God must have given it to us. That’s why the “test” argument does not make sense.