As I've explained a few times before, I believe the reformers came to the false conclusion of total depravity by making the simple mistake of assuming Adam and Eve were created in a state of moral righteousness. This is not the case at all, because it was when they ate the forbidden fruit that they were enlightened in their knowledge of good and evil. And so Adam and Eve were created in a state of moral innocence, similar to animals today. Adam and Eve could not be tempted with what was morally wrong if they were unable to understand right and wrong morally in the first place. God simply said, in the day you eat of this fruit, you will die.
So here's the key issue. If Adam and Eve had been created in a state of moral righteousness like the angels, then to reject this righteousness in favor of evil, they would then be in a state of moral unrighteousness which means they would be totally depraved, and would have no ability to be pleasing to God of themselves because they would now be in an eternal state of morally depravity.
Fallen angels are in this state, and there is no way to reverse it. If Adam and Eve were also in this state, there would be no way to reverse it for them either. This is where the reformers themselves haven't really got a clue what the basis is to reverse a person's state of moral depravity. There's no basis for it, but yet God does it in his infinite wisdom, which to us is nothing more than a divine lottery lacking in any kind of theological reasoning that makes any sense whatsoever
