In quantum error correction, we start with the fact that no-cloning theorem doesn't allow cloning of unknown states, hence we need to come up with other strategies.
But often we know the circuit that produces the state that we want to protect, so can't we just prepare the same state multiple times to in-effect clone it?
I realize that the circuits used for preparation would themselves incur error. But wouldn't there be a way to go around it by using more copies?
Is there a precise way to see that this pursuit is completely useless - perhaps one could show that there is no way to do this without using an exponential number of copies?