No. This works if you are able to tell a work of fiction and don't have to provide evidence.

And it works because we all know that repetition and practice are, in fact, important. So it feels believable that having people just repeat something over and over is the answer.

Similarly, people can be swayed by the master coming in and producing a single artifact that blows away everyone. You see this archetype story as often as the student that learns by just repeating a motion over and over. (Indeed.... this is literally the Karate Kid plot...)

The truth is far more mundane. Yes, you have to repeat things. But also yes, you have to give thought to what you are doing. This is why actual art classes aren't just "lets build things", but also "lets learn how to critique things that you build."

Isn't this a non-sequitur though? Artemis presumably doesn't have to actually load up humans on the rockets to flight test them.

It works perfectly well when you’ve got deep pockets and unmanned test vehicles though.