J2EE is a monstrosity, but this also highlights the point that we should stop using Hello World as an example for everything.

Enterprise software is inherently about "big" systems - for some definition of big. Using Hello world as an exemplar only sets up a strawman ripe for ridicule.

That said, the J2EE community does have a somewhat larger commonly known sample app - the Petstore - which ended up being a way to beat up J2EE more or less.