is the same thing

Nope. The thing is, it's not a "correct" -- "not correct" binary dilemma. For any reasonably complex problem there might be a single "correct" answer (provided what you consider optimal is fully specified) and a lot of different "technically not correct" answers. Those "technically not correct" answers are all different and will rise to different consequences. They are not the same -- and if getting the "technically correct" answer is unlikely, you do care about which "incorrect" answers you'll end up using.

Basically, diversification helps with dealing with the risks of having to accept "technically not correct" answers because the technically correct one is out of reach.