You can learn names and dates of battles etc., but you won’t understand the driving forces if all you have is “Nazis are bad.”
Nazis were humans, not some kind of mythological monsters. If they could do what they did, you can too. You need to understand why they did what they did, how the ideology motivated them, or compelled them, because those same forces can work on you as well, and sometimes in ways you don’t realize.
Primo Levi survived the death camps, and wrote about his experience extensively. Despite being a prisoner, he felt complicit in the Nazi project, just through trying to survive. At one point he recalls being on a work detail, during which he discovered a water pipe that had some water in it. He drank the water, and although he saw another prisoner lusting after the water, he didn’t share, because he wanted to survive.
That other man also survived the camps and later found Levi, and asked why he wouldn’t share the water. Levi had no answer at that time, but when writing his memoir he said the structure of the camp system was such that it employed even the inmates as agents of their own extermination.
He ended up committing suicide in the 80s.
If you don’t understand the psychological and social pressures working on you - which come from everywhere, btw, not just Nazis - you can’t fight against them. You will go along to get along.
So you know what Hitler actually said? So you don’t fall for something like “the Germans didn’t really know what was happening”? Yes, they did. It was published, and you can cite chapter and verse.
Same reason to read anything.