I'm not going to defend every last aspect of Java, but in practice verbosity and readability are not it's biggest issues. In practice Java is pretty maintainable and quick to write.
To address this strawman directly. The first and last line of the 'dreck' are the namespace, which is missing in the top function. I think it is entirely fair to omit namespace and access modifiers. Probably there needs to be <T extends Summable> or some such (ignoring a number of issues with the approach here), but then this could be put in the class declaration at the top for reuse in more than one function. Which would leave
static T Sum(T x, T y) { return x.add(y); }
Which is what it is ...