“Looks at SpaceX”, Iterate quickly and break things can work for rockets, it just depends on the development phase and the type of project. I wouldn’t “iterate quickly” with manned, extra terrestrial or important cargo missions.

But it can be used for the early development of rockets. Space X had a deep well of proven technology to draw upon during the development of the Falcon rocket. They put the tech together and iterated quickly to get a final product.

Blue Origin as well as the Artemis program both use traditional techniques with similar proven technologies. I’d argue they aren’t as successful or were never intended to be successful (Artemis is just a jobs program for shuttle contractors at this point).