Why do translations of German books read so differently from other books?

I’m unsure whether my question is on-topic here, but it’s about the German language, so I’ve decided to try.

I am an undergraduate student from Japan who learns foreign languages and loves reading books, especially historical ones. German is my third foreign language, so my German isn’t yet good enough to effortlessly read German books, but I’ve read translations of some books by Remarque, Manstein, Hitler, and Bismarck. My impression is that German books, at least in translation, read quite differently from other books. It isn’t a big stretch to say that I feel as if German books were written by aliens who think and express their thoughts differently from ordinary people. And my impression doesn’t change when I read German books in English translation rather than Japanese translation. I’ve read many English books in the original language, including such historical books as The Second World War by Churchill, July 1914: Countdown to War by McMeekin, and Narrative of events during the invasion of Russia by Napoleon Bonaparte and the retreat of the French Army 1812 by Wilson, so I’m pretty confident to say that English translations of German books read pretty different from English books, which I find to be quite naturally written.

I’m curious as to why translations of German books feel so different from other books. Is it at least partially due to the German language itself, or is it something purely culture-related that makes such a difference?

To illustrate what I am talking about, here’s a random sentence from an English translation of Bismarck’s Gedanken und Erinnerungen:

I put a few questions to Moltke as to the extent of his confidence in the state of our preparations, especially as to the time they would still require in order to meet this sudden risk of war.

That’s a very typical sentence from the book – a sentence that feels too artificial, bulky, and needlessly long. "Extent of his confidence in the state of our preparations," oh my God! I’d write much simpler: I asked Moltke how prepared our army was for war. That’s the real meaning in the context, as you can check by looking in the book. Everything I omitted in my own translation is either insignificant or obvious from the context anyway. If I were to emphasize the interest to know the time period needed to prepare for war, I’d still write something simple: I asked Moltke how prepared our army was, and, in particular, how long it would take to get ready for war. And even if I were to convey all unnecessary nuances, I’d still find a way to write something natural, like this: I asked Moltke a few questions about how prepared our army was and how sure he was about that, focusing on the time needed to get ready for such a risk of war.

I looked in the original German text, and here it is:

So as far I can judge, it isn’t a fault of the translator. He accurately translated what Bismarck had written.

Sure, the sentence in its accurate English translation doesn’t look weird to an extreme, but the thing is that when a whole book is written like that, it’s a pretty special read, so I wonder what makes German authors routinely express themselves in such a way. Is it just how the German language works, or is it rather a cultural tradition to write like that?

There are many other aspects that make German books feel different. For instance, the sense of obligation is very often referred or appealed to in German books, explicitly or implicitly, or at least that’s my impression from translations. More broadly, the way of thinking underlying writings of German authors seems to be tied to some set of unwritten principles or rules according to which decisions in life should be taken or how things should be. A contrast is often made between how things should be and how they actually are, and this results in a flavor of overall gloom.

I hope that German speakers can offer their perspective as to why translations of German books read differently from other books. Is it due to the German language itself shaping the way of expressing thoughts? Or do accurate English translations of German texts actually misrepresent them in terms of style and emotional connotations? Or is the effect due to cultural factors?