the exact details of EU copyright rules and lengths are probably difficult to work out, at least as difficult as saying what the laws are regarding what constitutes a felony in the United States, since that really depends on what state you're in.

But I would have to say that yes, it is mainly the EU that drives longer copyright, because EU copyright is not based on a model of doing things to help society but because there is a moral right of ownership that is possessed by the creator of a work. This of course explains why often something is out of copyright in the U.S but still under copyright in the EU but I don't think I have ever heard of the reverse applying (I'm sure HN can come up with an edge case though)

The situation with public domain in part because most US government works are public domain and PD isn’t even possible in some European countries—related to moral rights.