I mean Americans are more likely to strike up a conversation with a stranger than a German and they will probably be more polite while doing it.
As a country, the US is much crueller than Germany though. I'm not going to tell you that Germany is perfect, but there are expectations about what is acceptable that simply don't exist in the US. If you visit the US you're going to be overwhelmed by the sheer number of homeless people and particularly the number of homeless people on crutches, because it's ok not to give them needed medical aid. Similarly there's an overwhelming number of school shootings where every other country has simply stopped them via gun control. You also have basically no workers rights compared to Europe and if you're poor it's assumed to be your fault.
Again, you will see aspects of this in Germany, but the US simply has many of the worse aspects turned up to 11.