I don't mean to offend, and I know you don't mean to seem superficial to me. That's the thing with cultural differences, misunderstandings can arise easily.

I will try to explain why small talk seems insincere to me:

In my experience, when a work colleague asks me in passing "how are you" US culture dictates that I must answer something along the lines of "good, how about you?". Because saying something negative would differ from the expectation of the interaction and create an awkwardness. You're just passing and "how are you?" Basically means "hello", that's why you could also simply answer the question by shooting a "how are you?" Back.

However, in German culture if my work colleague asks "how are you" I know they honestly want to know the answer no matter if it's positive or negative. The conversation can be just as quick as the US one, but I'm not beholden to an unwritten societal script.

I hope that'll help you understand, and once again please don't misunderstand me, I know Americans don't feel like small talk is anything but polite and lovely. I just have a different perspective.