Steven Spielberg said, after he made Schindler's List, that it was partly an apology for portraying Nazis in the Indiana Jones franchise as less evil than they really were. I think Hollywood has been guilty of something far worse in recent decades: portraying Nazis as competent.

Germany wasn't a country run by Nazis that happened to lose the Second World War, it was a country that lost because it was run by Nazis.

Take a look at the names of the folks that worked on the Manhattan Project. See how many of them are German? Several of them worked on weapons in the First World War, for the Germans. Germany had a huge lead in developing a nuclear weapon in the '30s, but removed people who weren't Nazi enough from positions of authority in fields related to weapons research. A load of their best scientists were on the various lists that would end up on death camps and managed to leave (others didn't, and died). When you start by saying 'only people from this arbitrary subset of the population based on race / gender / religion / sexuality / whatever may contribute to our society', you won't get the best people.

Hitler maintained control by promoting people based on their personal loyalty to him, not based on their competence. He ensured communication flowed through him and made parallel agencies compete, directing their effort against each other rather than towards shared goals, to avoid any becoming powerful enough to challenge his power structures.

Hitler was almost responsible for most of the German army being wiped out early on in the Second World War because he had an exaggerated opinion of his own ability. The only reason it wasn't was that allied commanders didn't believe anyone could be that stupid and assumed it was a trap (it wasn't, he really was that stupid). He then decided to invade Russia in the winter (which worked so well for Napoleon) against the advice of any of the people who paid attention in school, which was one of the key turning points in the war.

Don't let the smart uniforms fool you. They were not competent people who lost as a result of circumstances beyond their control. They were people with an ideology that was ultimately self defeating in the long term. And, if people with the same views are in positions of power again, they will fail in the same way. The problem is not that they might succeed, it's that they have a habit of taking a lot of other people with them on their way to defeat.